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<!-- DFIN ActiveDisclosure(SM) XBRL Linkbase Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2021-02-05T21:52:33.4426266+00:00 -->
<!-- Version            : 5.0.1.571 -->
<!-- Package ID         : c7364437af074432a4a571e2f16dd8a5 -->
<!-- Copyright (c) 2021 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
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    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityAddressPostalZipCode" xlink:type="locator" xlink:label="dei_EntityAddressPostalZipCode" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressPostalZipCode_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, Postal Zip Code</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressPostalZipCode" xlink:to="dei_EntityAddressPostalZipCode_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressPostalZipCode_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address Postal Zip Code</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_CityAreaCode" xlink:type="locator" xlink:label="dei_CityAreaCode" />
    <link:label xml:lang="en-US" xlink:label="dei_CityAreaCode_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">City Area Code</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CityAreaCode" xlink:to="dei_CityAreaCode_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_CityAreaCode_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">City Area Code</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LocalPhoneNumber" xlink:type="locator" xlink:label="dei_LocalPhoneNumber" />
    <link:label xml:lang="en-US" xlink:label="dei_LocalPhoneNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Local Phone Number</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LocalPhoneNumber" xlink:to="dei_LocalPhoneNumber_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_LocalPhoneNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Local Phone Number</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_TradingSymbol" xlink:type="locator" xlink:label="dei_TradingSymbol" />
    <link:label xml:lang="en-US" xlink:label="dei_TradingSymbol_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trading Symbol</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_TradingSymbol" xlink:to="dei_TradingSymbol_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_TradingSymbol_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Trading Symbol</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_SecurityExchangeName" xlink:type="locator" xlink:label="dei_SecurityExchangeName" />
    <link:label xml:lang="en-US" xlink:label="dei_SecurityExchangeName_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Security Exchange Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_SecurityExchangeName" xlink:to="dei_SecurityExchangeName_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_SecurityExchangeName_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Security Exchange Name</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_Security12bTitle" xlink:type="locator" xlink:label="dei_Security12bTitle" />
    <link:label xml:lang="en-US" xlink:label="dei_Security12bTitle_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Title of 12(b) Security</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_Security12bTitle" xlink:to="dei_Security12bTitle_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_Security12bTitle_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Security12b Title</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:type="locator" xlink:label="dei_EntityWellKnownSeasonedIssuer" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityWellKnownSeasonedIssuer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Well-known Seasoned Issuer</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityWellKnownSeasonedIssuer" xlink:to="dei_EntityWellKnownSeasonedIssuer_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityWellKnownSeasonedIssuer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Well Known Seasoned Issuer</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityVoluntaryFilers" xlink:type="locator" xlink:label="dei_EntityVoluntaryFilers" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityVoluntaryFilers_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Voluntary Filers</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityVoluntaryFilers" xlink:to="dei_EntityVoluntaryFilers_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityVoluntaryFilers_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Voluntary Filers</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_IcfrAuditorAttestationFlag" xlink:type="locator" xlink:label="dei_IcfrAuditorAttestationFlag" />
    <link:label xml:lang="en-US" xlink:label="dei_IcfrAuditorAttestationFlag_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ICFR Auditor Attestation Flag</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_IcfrAuditorAttestationFlag" xlink:to="dei_IcfrAuditorAttestationFlag_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_IcfrAuditorAttestationFlag_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Icfr Auditor Attestation Flag</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityPublicFloat" xlink:type="locator" xlink:label="dei_EntityPublicFloat" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityPublicFloat_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Entity Public Float</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityPublicFloat" xlink:to="dei_EntityPublicFloat_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityPublicFloat_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Public Float</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:type="locator" xlink:label="dei_EntityCommonStockSharesOutstanding" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Entity Common Stock, Shares Outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCommonStockSharesOutstanding" xlink:to="dei_EntityCommonStockSharesOutstanding_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Common Stock Shares Outstanding</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RevenueFromContractWithCustomerBeforeReimbursementsExcludingAssessedTax" xlink:type="locator" xlink:label="ajg_RevenueFromContractWithCustomerBeforeReimbursementsExcludingAssessedTax" />
    <link:label xml:lang="en-US" xlink:label="ajg_RevenueFromContractWithCustomerBeforeReimbursementsExcludingAssessedTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Revenue from contract with customer before reimbursements , excluding assessed Tax.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RevenueFromContractWithCustomerBeforeReimbursementsExcludingAssessedTax" xlink:to="ajg_RevenueFromContractWithCustomerBeforeReimbursementsExcludingAssessedTax_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RevenueFromContractWithCustomerExcludingAssessedTaxReimbursements" xlink:type="locator" xlink:label="ajg_RevenueFromContractWithCustomerExcludingAssessedTaxReimbursements" />
    <link:label xml:lang="en-US" xlink:label="ajg_RevenueFromContractWithCustomerExcludingAssessedTaxReimbursements_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Revenue from contract with customer excluding assessed tax reimbursements.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RevenueFromContractWithCustomerExcludingAssessedTaxReimbursements" xlink:to="ajg_RevenueFromContractWithCustomerExcludingAssessedTaxReimbursements_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CostReimbursements" xlink:type="locator" xlink:label="ajg_CostReimbursements" />
    <link:label xml:lang="en-US" xlink:label="ajg_CostReimbursements_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cost reimbursements.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CostReimbursements" xlink:to="ajg_CostReimbursements_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ChangeInEstimatedAcquisitionEarnoutPayables" xlink:type="locator" xlink:label="ajg_ChangeInEstimatedAcquisitionEarnoutPayables" />
    <link:label xml:lang="en-US" xlink:label="ajg_ChangeInEstimatedAcquisitionEarnoutPayables_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Change in estimated acquisition earnout payables</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ChangeInEstimatedAcquisitionEarnoutPayables" xlink:to="ajg_ChangeInEstimatedAcquisitionEarnoutPayables_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:type="locator" xlink:label="us-gaap_IncomeStatementAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeStatementAbstract_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statement [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductOrServiceAxis" xlink:type="locator" xlink:label="srt_ProductOrServiceAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_ProductOrServiceAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product and Service</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductOrServiceAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ProductOrServiceAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Product Or Service [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:type="locator" xlink:label="srt_ProductsAndServicesDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_ProductsAndServicesDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product and Service</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductsAndServicesDomain" xlink:to="srt_ProductsAndServicesDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ProductsAndServicesDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Products And Services [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CommissionsMember" xlink:type="locator" xlink:label="ajg_CommissionsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CommissionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Commissions [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CommissionsMember" xlink:to="ajg_CommissionsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CommissionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commissions [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CommissionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Commissions [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BrokerFeesMember" xlink:type="locator" xlink:label="ajg_BrokerFeesMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_BrokerFeesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Broker Fees [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BrokerFeesMember" xlink:to="ajg_BrokerFeesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_BrokerFeesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Broker Fees [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BrokerFeesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Broker Fees [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_SupplementalRevenueMember" xlink:type="locator" xlink:label="ajg_SupplementalRevenueMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_SupplementalRevenueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Supplemental revenue.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_SupplementalRevenueMember" xlink:to="ajg_SupplementalRevenueMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_SupplementalRevenueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Supplemental Revenue [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_SupplementalRevenueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Supplemental Revenue [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ContingentRevenueMember" xlink:type="locator" xlink:label="ajg_ContingentRevenueMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_ContingentRevenueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Contingent Revenue [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ContingentRevenueMember" xlink:to="ajg_ContingentRevenueMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ContingentRevenueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contingent Revenue [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ContingentRevenueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contingent Revenue [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentPerformanceMember" xlink:type="locator" xlink:label="us-gaap_InvestmentPerformanceMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentPerformanceMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment income [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentPerformanceMember" xlink:to="us-gaap_InvestmentPerformanceMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentPerformanceMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investment Performance [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_GainsOnDivestituresMember" xlink:type="locator" xlink:label="ajg_GainsOnDivestituresMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_GainsOnDivestituresMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Gains On Divestitures [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_GainsOnDivestituresMember" xlink:to="ajg_GainsOnDivestituresMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_GainsOnDivestituresMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net (Losses) Gains on Divestitures [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_GainsOnDivestituresMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Gains On Divestitures [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PublicUtilitiesInventoryCoalMember" xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesInventoryCoalMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PublicUtilitiesInventoryCoalMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Clean Coal Activities [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesInventoryCoalMember" xlink:to="us-gaap_PublicUtilitiesInventoryCoalMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PublicUtilitiesInventoryCoalMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Public Utilities Inventory Coal [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductAndServiceOtherMember" xlink:type="locator" xlink:label="us-gaap_ProductAndServiceOtherMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProductAndServiceOtherMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other net (losses) revenue [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductAndServiceOtherMember" xlink:to="us-gaap_ProductAndServiceOtherMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProductAndServiceOtherMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Product And Service Other [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementLineItems_lbl" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" xlink:to="us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:type="locator" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Comprehensive earnings attributable to controlling interests</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_ComprehensiveIncomeNetOfTax_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Comprehensive Income Net Of Tax</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PremiumsPayableToUnderwritingEnterprises" xlink:type="locator" xlink:label="ajg_PremiumsPayableToUnderwritingEnterprises" />
    <link:label xml:lang="en-US" xlink:label="ajg_PremiumsPayableToUnderwritingEnterprises_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Premiums payable to underwriting enterprises.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PremiumsPayableToUnderwritingEnterprises" xlink:to="ajg_PremiumsPayableToUnderwritingEnterprises_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AccruedCompensationAndOtherAccruedLiabilities" xlink:type="locator" xlink:label="ajg_AccruedCompensationAndOtherAccruedLiabilities" />
    <link:label xml:lang="en-US" xlink:label="ajg_AccruedCompensationAndOtherAccruedLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Accrued compensation and other accrued liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AccruedCompensationAndOtherAccruedLiabilities" xlink:to="ajg_AccruedCompensationAndOtherAccruedLiabilities_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PremiumFinancingBorrowings" xlink:type="locator" xlink:label="ajg_PremiumFinancingBorrowings" />
    <link:label xml:lang="en-US" xlink:label="ajg_PremiumFinancingBorrowings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Premium financing borrowings.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PremiumFinancingBorrowings" xlink:to="ajg_PremiumFinancingBorrowings_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Of Financial Position [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementOfFinancialPositionAbstract_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash and cash equivalents</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash And Cash Equivalents At Carrying Value</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedCashCurrent" xlink:type="locator" xlink:label="us-gaap_RestrictedCashCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedCashCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted cash</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedCashCurrent" xlink:to="us-gaap_RestrictedCashCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedCashCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Cash Current</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PremiumsAndOtherReceivablesNet" xlink:type="locator" xlink:label="us-gaap_PremiumsAndOtherReceivablesNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PremiumsAndOtherReceivablesNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Premiums and fees receivable</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PremiumsAndOtherReceivablesNet" xlink:to="us-gaap_PremiumsAndOtherReceivablesNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PremiumsAndOtherReceivablesNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Premiums And Other Receivables Net</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:type="locator" xlink:label="us-gaap_OtherAssetsCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsCurrent" xlink:to="us-gaap_OtherAssetsCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Assets Current</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsCurrent" xlink:type="locator" xlink:label="us-gaap_AssetsCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Assets Current</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed assets - net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Net</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredIncomeTaxAssetsNet" xlink:type="locator" xlink:label="us-gaap_DeferredIncomeTaxAssetsNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredIncomeTaxAssetsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred income taxes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxAssetsNet" xlink:to="us-gaap_DeferredIncomeTaxAssetsNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredIncomeTaxAssetsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Income Tax Assets Net</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:type="locator" xlink:label="us-gaap_OtherAssetsNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other noncurrent assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsNoncurrent" xlink:to="us-gaap_OtherAssetsNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Assets Noncurrent</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseRightOfUseAsset" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Right Of Use Asset</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:type="locator" xlink:label="us-gaap_Goodwill" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Goodwill_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill - net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Goodwill" xlink:to="us-gaap_Goodwill_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Goodwill_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortizable intangible assets - net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finite Lived Intangible Assets Net</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Assets" xlink:type="locator" xlink:label="us-gaap_Assets" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Assets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Assets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Assets</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PremiumsPayableToUnderwritingEnterprises_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Premiums payable to underwriting enterprises</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PremiumsPayableToUnderwritingEnterprises_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Premiums Payable To Underwriting Enterprises</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AccruedCompensationAndOtherAccruedLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued compensation and other accrued liabilities</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AccruedCompensationAndOtherAccruedLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Compensation And Other Accrued Liabilities</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredRevenueCurrent" xlink:type="locator" xlink:label="us-gaap_DeferredRevenueCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue - current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueCurrent" xlink:to="us-gaap_DeferredRevenueCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue Current</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PremiumFinancingBorrowings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Premium financing borrowings</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PremiumFinancingBorrowings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Premium Financing Borrowings</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShortTermBorrowings" xlink:type="locator" xlink:label="us-gaap_ShortTermBorrowings" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShortTermBorrowings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Corporate related borrowings - current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermBorrowings" xlink:to="us-gaap_ShortTermBorrowings_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShortTermBorrowings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Short Term Borrowings</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_LiabilitiesCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities Current</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:type="locator" xlink:label="us-gaap_LongTermDebtNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Corporate related borrowings - noncurrent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtNoncurrent" xlink:to="us-gaap_LongTermDebtNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Noncurrent</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredRevenueNoncurrent" xlink:type="locator" xlink:label="us-gaap_DeferredRevenueNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue - noncurrent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueNoncurrent" xlink:to="us-gaap_DeferredRevenueNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue Noncurrent</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lease liabilities - noncurrent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Liability Noncurrent</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_OtherLiabilitiesNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other noncurrent liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesNoncurrent" xlink:to="us-gaap_OtherLiabilitiesNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Liabilities Noncurrent</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:type="locator" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Stockholders&apos; equity attributable to controlling interests</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stockholders Equity</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MinorityInterest" xlink:type="locator" xlink:label="us-gaap_MinorityInterest" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stockholders&apos; equity attributable to noncontrolling interests</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterest" xlink:to="us-gaap_MinorityInterest_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Minority Interest</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total stockholders&apos; equity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stockholders Equity Including Portion Attributable To Noncontrolling Interest</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:type="locator" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities and stockholders&apos; equity</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities And Stockholders Equity</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock - authorized shares</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Shares Authorized</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesIssued" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock - issued shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesIssued" xlink:to="us-gaap_CommonStockSharesIssued_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Shares Issued</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesOutstanding" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock - outstanding shares</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Shares Outstanding</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AmortizationOfDeferredCompensationAndRestrictedStock" xlink:type="locator" xlink:label="ajg_AmortizationOfDeferredCompensationAndRestrictedStock" />
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_IncreaseDecreaseInPremiumsAndFeeReceivable" xlink:type="locator" xlink:label="ajg_IncreaseDecreaseInPremiumsAndFeeReceivable" />
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_NetChangeInAccruedCompensationAndOtherAccruedLiabilities" xlink:type="locator" xlink:label="ajg_NetChangeInAccruedCompensationAndOtherAccruedLiabilities" />
    <link:label xml:lang="en-US" xlink:label="ajg_NetChangeInAccruedCompensationAndOtherAccruedLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Net change in accrued compensation and other accrued liabilities</link:label>
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_PaymentsToAcquireBusinessesNetOfCashAndRestrictedCashAcquired" xlink:type="locator" xlink:label="ajg_PaymentsToAcquireBusinessesNetOfCashAndRestrictedCashAcquired" />
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_NetProceedsFromSalesOfOperations" xlink:type="locator" xlink:label="ajg_NetProceedsFromSalesOfOperations" />
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_EarnoutPaymentsForAcquisitions" xlink:type="locator" xlink:label="ajg_EarnoutPaymentsForAcquisitions" />
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_NetBorrowingsOnPremiumFinancingDebtFacility" xlink:type="locator" xlink:label="ajg_NetBorrowingsOnPremiumFinancingDebtFacility" />
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_PaymentsForProceedsFromSettlementsOfTerminatedInterestRateSwaps" xlink:type="locator" xlink:label="ajg_PaymentsForProceedsFromSettlementsOfTerminatedInterestRateSwaps" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PaymentsForProceedsFromSettlementsOfTerminatedInterestRateSwaps" xlink:to="ajg_PaymentsForProceedsFromSettlementsOfTerminatedInterestRateSwaps_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfCashFlowsAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Of Cash Flows [Abstract]</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from operating activities:</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided By Used In Operating Activities [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="locator" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnInvestments" xlink:type="locator" xlink:label="us-gaap_GainLossOnInvestments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainLossOnInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Net loss (gain) on investments and other</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_GainLossOnInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Gain Loss On Investments</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DepreciationAmortizationAndAccretionNet" xlink:type="locator" xlink:label="us-gaap_DepreciationAmortizationAndAccretionNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DepreciationAmortizationAndAccretionNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation and amortization</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DepreciationAmortizationAndAccretionNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Depreciation Amortization And Accretion Net</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmortizationOfDeferredCompensationAndRestrictedStock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of deferred compensation and restricted stock</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmortizationOfDeferredCompensationAndRestrictedStock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Amortization Of Deferred Compensation And Restricted Stock</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossUnrealized" xlink:type="locator" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossUnrealized" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInContractWithCustomerLiability" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInReinsurancePayables" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInReinsurancePayables" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncreaseDecreaseInReinsurancePayables_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net change in premiums payable to underwriting enterprises</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInDeferredIncomeTaxes" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInDeferredIncomeTaxes" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash provided by operating activities</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided By Used In Operating Activities</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from investing activities:</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided By Used In Investing Activities [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForCapitalImprovements" xlink:type="locator" xlink:label="us-gaap_PaymentsForCapitalImprovements" />
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    <link:label xml:lang="en-US" xlink:label="ajg_PaymentsToAcquireBusinessesNetOfCashAndRestrictedCashAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Cash paid for acquisitions, net of cash and restricted cash acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PaymentsToAcquireBusinessesNetOfCashAndRestrictedCashAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Payments To Acquire Businesses Net Of Cash And Restricted Cash Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NetProceedsFromSalesOfOperations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net proceeds from sales of operations/books of business</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_PaymentsForProceedsFromInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Net funding of investment transactions</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash used by investing activities</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided By Used In Investing Activities</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from financing activities:</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided By Used In Financing Activities [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EarnoutPaymentsForAcquisitions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Payments on acquisition earnouts</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromLinesOfCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Borrowings on line of credit facility</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromLinesOfCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Lines Of Credit</link:label>
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_ComponentsOfPeriodicPensionBenefitCostAndOtherChangesInPlanAssetsAndObligationsRecognizedInEarningsAndOtherComprehensiveEarningsTableTextBlock" xlink:type="locator" xlink:label="ajg_ComponentsOfPeriodicPensionBenefitCostAndOtherChangesInPlanAssetsAndObligationsRecognizedInEarningsAndOtherComprehensiveEarningsTableTextBlock" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ExpirationListsMember" xlink:to="ajg_ExpirationListsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ExpirationListsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expiration Lists [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ExpirationListsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Expiration Lists [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncompeteAgreementsMember" xlink:type="locator" xlink:label="us-gaap_NoncompeteAgreementsMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NoncompeteAgreementsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-Compete Agreements [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncompeteAgreementsMember" xlink:to="us-gaap_NoncompeteAgreementsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NoncompeteAgreementsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Noncompete Agreements [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TradeNamesMember" xlink:type="locator" xlink:label="us-gaap_TradeNamesMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TradeNamesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trade Names [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TradeNamesMember" xlink:to="us-gaap_TradeNamesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TradeNamesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Trade Names [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOwnershipPlanESOPDisclosuresByPlanAxis" xlink:type="locator" xlink:label="us-gaap_EmployeeStockOwnershipPlanESOPDisclosuresByPlanAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmployeeStockOwnershipPlanESOPDisclosuresByPlanAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee Stock Ownership Plan (ESOP) Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeStockOwnershipPlanESOPDisclosuresByPlanAxis" xlink:to="us-gaap_EmployeeStockOwnershipPlanESOPDisclosuresByPlanAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmployeeStockOwnershipPlanESOPDisclosuresByPlanAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Employee Stock Ownership Plan E S O P Disclosures By Plan [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOwnershipPlanESOPPlanDomain" xlink:type="locator" xlink:label="us-gaap_EmployeeStockOwnershipPlanESOPPlanDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmployeeStockOwnershipPlanESOPPlanDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee Stock Ownership Plan (ESOP), Plan</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeStockOwnershipPlanESOPPlanDomain" xlink:to="us-gaap_EmployeeStockOwnershipPlanESOPPlanDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmployeeStockOwnershipPlanESOPPlanDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Employee Stock Ownership Plan E S O P Plan [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_EmployeeStockPurchasePlanMember" xlink:type="locator" xlink:label="ajg_EmployeeStockPurchasePlanMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_EmployeeStockPurchasePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Employee Stock Purchase Plan [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_EmployeeStockPurchasePlanMember" xlink:to="ajg_EmployeeStockPurchasePlanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_EmployeeStockPurchasePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee Stock Purchase Plan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EmployeeStockPurchasePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Employee Stock Purchase Plan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_SignificantAccountingPoliciesLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Significant Accounting Policies [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_SignificantAccountingPoliciesLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Significant Accounting Policies [Line Items]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NumberOfReportableSegments" xlink:type="locator" xlink:label="us-gaap_NumberOfReportableSegments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of reportable segments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfReportableSegments" xlink:to="us-gaap_NumberOfReportableSegments_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Reportable Segments</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfCommercialCleanCoalProductionFacilities" xlink:type="locator" xlink:label="ajg_NumberOfCommercialCleanCoalProductionFacilities" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCommercialCleanCoalProductionFacilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of commercial clean coal production facilities.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfCommercialCleanCoalProductionFacilities" xlink:to="ajg_NumberOfCommercialCleanCoalProductionFacilities_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCommercialCleanCoalProductionFacilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of commercial clean coal production facilities</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCommercialCleanCoalProductionFacilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Commercial Clean Coal Production Facilities</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfCountriesInWhichCompanyHasOperations" xlink:type="locator" xlink:label="ajg_NumberOfCountriesInWhichCompanyHasOperations" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCountriesInWhichCompanyHasOperations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of Countries in which the Company has Operations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfCountriesInWhichCompanyHasOperations" xlink:to="ajg_NumberOfCountriesInWhichCompanyHasOperations_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfCountriesInWhichCompanyDoesBusinessThroughNetworkOfCorrespondentBrokersAndConsultants" xlink:type="locator" xlink:label="ajg_NumberOfCountriesInWhichCompanyDoesBusinessThroughNetworkOfCorrespondentBrokersAndConsultants" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCountriesInWhichCompanyDoesBusinessThroughNetworkOfCorrespondentBrokersAndConsultants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of Countries in which the Company does Business through a Network of Correspondent Brokers and Consultants</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfCountriesInWhichCompanyDoesBusinessThroughNetworkOfCorrespondentBrokersAndConsultants" xlink:to="ajg_NumberOfCountriesInWhichCompanyDoesBusinessThroughNetworkOfCorrespondentBrokersAndConsultants_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCountriesInWhichCompanyHasOperations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of countries in which the company has operations</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCountriesInWhichCompanyHasOperations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Countries In Which Company Has Operations</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCountriesInWhichCompanyDoesBusinessThroughNetworkOfCorrespondentBrokersAndConsultants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of countries in which the company does business through a network of correspondent brokers and consultants</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCountriesInWhichCompanyDoesBusinessThroughNetworkOfCorrespondentBrokersAndConsultants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Countries In Which Company Does Business Through Network Of Correspondent Brokers And Consultants</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of ownership interest</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:to="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Ownership Percentage</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableInterestEntityOwnershipPercentage" xlink:type="locator" xlink:label="us-gaap_VariableInterestEntityOwnershipPercentage" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_VariableInterestEntityOwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of variable ownership interest</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableInterestEntityOwnershipPercentage" xlink:to="us-gaap_VariableInterestEntityOwnershipPercentage_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_VariableInterestEntityOwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Variable Interest Entity Ownership Percentage</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DescriptionOfContractsRenewalPeriod" xlink:type="locator" xlink:label="ajg_DescriptionOfContractsRenewalPeriod" />
    <link:label xml:lang="en-US" xlink:label="ajg_DescriptionOfContractsRenewalPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Description of contracts renewal period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DescriptionOfContractsRenewalPeriod" xlink:to="ajg_DescriptionOfContractsRenewalPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_DescriptionOfContractsRenewalPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Description of contracts renewal period</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DescriptionOfContractsRenewalPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Description Of Contracts Renewal Period</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedOnEffectiveDateOfInsuranceContract" xlink:type="locator" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedOnEffectiveDateOfInsuranceContract" />
    <link:label xml:lang="en-US" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedOnEffectiveDateOfInsuranceContract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of Commissions and fee revenues recognized on the effective date of the underlying insurance contract.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedOnEffectiveDateOfInsuranceContract" xlink:to="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedOnEffectiveDateOfInsuranceContract_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedInFirstThreeMonthsOfInsuranceContract" xlink:type="locator" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedInFirstThreeMonthsOfInsuranceContract" />
    <link:label xml:lang="en-US" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedInFirstThreeMonthsOfInsuranceContract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of Commissions and fee revenues recognized in the first three months of the underlying insurance contract.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedInFirstThreeMonthsOfInsuranceContract" xlink:to="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedInFirstThreeMonthsOfInsuranceContract_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedAfterFirstThreeMonthsOfInsuranceContract" xlink:type="locator" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedAfterFirstThreeMonthsOfInsuranceContract" />
    <link:label xml:lang="en-US" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedAfterFirstThreeMonthsOfInsuranceContract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of Commissions and fee revenues recognized after the first three months of the underlying insurance contract.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedAfterFirstThreeMonthsOfInsuranceContract" xlink:to="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedAfterFirstThreeMonthsOfInsuranceContract_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedOnEffectiveDateOfInsuranceContract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of commission and fee revenues on the effective date</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedOnEffectiveDateOfInsuranceContract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Commissions And Fee Revenues Recognized On Effective Date Of Insurance Contract</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedInFirstThreeMonthsOfInsuranceContract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of commission and fee revenues in the first three months</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedInFirstThreeMonthsOfInsuranceContract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Commissions And Fee Revenues Recognized In First Three Months Of Insurance Contract</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedAfterFirstThreeMonthsOfInsuranceContract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of commission and fee revenues after the first three months</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PercentageOfCommissionsAndFeeRevenuesRecognizedAfterFirstThreeMonthsOfInsuranceContract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Commissions And Fee Revenues Recognized After First Three Months Of Insurance Contract</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AllowancesForEstimatedPolicyCancellations" xlink:type="locator" xlink:label="ajg_AllowancesForEstimatedPolicyCancellations" />
    <link:label xml:lang="en-US" xlink:label="ajg_AllowancesForEstimatedPolicyCancellations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Allowances for Estimated Policy Cancellations.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AllowancesForEstimatedPolicyCancellations" xlink:to="ajg_AllowancesForEstimatedPolicyCancellations_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_AllowancesForEstimatedPolicyCancellations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Allowances for estimated policy cancellations</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AllowancesForEstimatedPolicyCancellations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Allowances For Estimated Policy Cancellations</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:type="locator" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Allowance for doubtful accounts</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Allowance For Doubtful Accounts Receivable</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InsuranceContractsPremiumFinancingTerms" xlink:type="locator" xlink:label="ajg_InsuranceContractsPremiumFinancingTerms" />
    <link:label xml:lang="en-US" xlink:label="ajg_InsuranceContractsPremiumFinancingTerms_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Premium financing contracts are structured to minimize potential bad debt expense. Such receivables are generally considered delinquent after seven days of the payment due date.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InsuranceContractsPremiumFinancingTerms" xlink:to="ajg_InsuranceContractsPremiumFinancingTerms_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_InsuranceContractsPremiumFinancingTerms_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Premium financing contracts, terms</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InsuranceContractsPremiumFinancingTerms_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Insurance Contracts Premium Financing Terms</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsReceivableBilledForLongTermContractsOrPrograms" xlink:type="locator" xlink:label="us-gaap_AccountsReceivableBilledForLongTermContractsOrPrograms" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccountsReceivableBilledForLongTermContractsOrPrograms_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Outstanding loan receivable</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableBilledForLongTermContractsOrPrograms" xlink:to="us-gaap_AccountsReceivableBilledForLongTermContractsOrPrograms_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccountsReceivableBilledForLongTermContractsOrPrograms_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Receivable Billed For Long Term Contracts Or Programs</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RegulatoryAssetsAbstract" xlink:type="locator" xlink:label="ajg_RegulatoryAssetsAbstract" />
    <link:label xml:lang="en-US" xlink:label="ajg_RegulatoryAssetsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Regulatory Assets [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RegulatoryAssetsAbstract" xlink:to="ajg_RegulatoryAssetsAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_RegulatoryAssetsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Regulatory Assets [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Property Plant And Equipment [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Property Plant And Equipment [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Lived Tangible Asset</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment By Type [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Lived Tangible Asset</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Type [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OfficeEquipmentMember" xlink:type="locator" xlink:label="us-gaap_OfficeEquipmentMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OfficeEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Office Equipment [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OfficeEquipmentMember" xlink:to="us-gaap_OfficeEquipmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OfficeEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Office Equipment [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:type="locator" xlink:label="us-gaap_FurnitureAndFixturesMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FurnitureAndFixturesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Furniture and Fixtures [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FurnitureAndFixturesMember" xlink:to="us-gaap_FurnitureAndFixturesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FurnitureAndFixturesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Furniture And Fixtures [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ComputerEquipmentMember" xlink:type="locator" xlink:label="us-gaap_ComputerEquipmentMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ComputerEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Computer Equipment [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComputerEquipmentMember" xlink:to="us-gaap_ComputerEquipmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ComputerEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Computer Equipment [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BuildingMember" xlink:type="locator" xlink:label="us-gaap_BuildingMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BuildingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Building [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BuildingMember" xlink:to="us-gaap_BuildingMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BuildingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Building [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SoftwareDevelopmentMember" xlink:type="locator" xlink:label="us-gaap_SoftwareDevelopmentMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SoftwareDevelopmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Software [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SoftwareDevelopmentMember" xlink:to="us-gaap_SoftwareDevelopmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SoftwareDevelopmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Software Development [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RefinedFuelPlantsMember" xlink:type="locator" xlink:label="ajg_RefinedFuelPlantsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_RefinedFuelPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Refined Fuel Plants [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RefinedFuelPlantsMember" xlink:to="ajg_RefinedFuelPlantsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_RefinedFuelPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Refined Fuel Plants [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RefinedFuelPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Refined Fuel Plants [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:type="locator" xlink:label="us-gaap_LeaseholdImprovementsMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LeaseholdImprovementsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Leasehold Improvements [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseholdImprovementsMember" xlink:to="us-gaap_LeaseholdImprovementsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LeaseholdImprovementsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Leasehold Improvements [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, Plant and Equipment [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment [Line Items]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Useful life, years</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Useful Life</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated useful lives, years</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives" xlink:to="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Estimated Useful Lives</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated useful lives of intangibles assets, years</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:to="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finite Lived Intangible Asset Useful Life</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived" xlink:type="locator" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsFinitelived" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsFinitelived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Write-off of amortizable intangible assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ImpairmentOfIntangibleAssetsFinitelived" xlink:to="us-gaap_ImpairmentOfIntangibleAssetsFinitelived_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsFinitelived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Impairment Of Intangible Assets Finitelived</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairMarketValue" xlink:type="locator" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairMarketValue" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairMarketValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share-Based Compensation Arrangement By Share-Based Payment Award, Aggregate Fair Market Value.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairMarketValue" xlink:to="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairMarketValue_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares authorized</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of employees contribution</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Maximum Employee Subscription Rate</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price of common stock, percentage</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Discount From Market Price Offering Date</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairMarketValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate fair market value of shares purchased</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairMarketValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Aggregate Fair Market Value</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum number of shares purchased by employees</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Maximum Number Of Shares Per Employee</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares available for grant</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesAbstract" xlink:type="locator" xlink:label="us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">New Accounting Pronouncements And Changes In Accounting Principles [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesAbstract" xlink:to="us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesAbstract_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable" xlink:type="locator" xlink:label="us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">New Accounting Pronouncements Or Change In Accounting Principle [Table]</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CRESInsuranceServicesLLCMember" xlink:to="ajg_CRESInsuranceServicesLLCMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CRESInsuranceServicesLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">CRES Insurance Services, LLC (CRES) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CRESInsuranceServicesLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">C R E S Insurance Services L L C [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_OptimumTalentIncMember" xlink:type="locator" xlink:label="ajg_OptimumTalentIncMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_OptimumTalentIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Optimum Talent Inc.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_OptimumTalentIncMember" xlink:to="ajg_OptimumTalentIncMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_OptimumTalentIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Optimum Talent Inc. (OTI) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_OptimumTalentIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Optimum Talent Inc [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AshtonTiffanyLLCMember" xlink:type="locator" xlink:label="ajg_AshtonTiffanyLLCMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_AshtonTiffanyLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Ashton Tiffany, LLC.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AshtonTiffanyLLCMember" xlink:to="ajg_AshtonTiffanyLLCMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_AshtonTiffanyLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Ashton Tiffany, LLC (AT) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AshtonTiffanyLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Ashton Tiffany L L C [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CoolInsuringAgencyIncMember" xlink:type="locator" xlink:label="ajg_CoolInsuringAgencyIncMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CoolInsuringAgencyIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cool Insuring Agency, Inc.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CoolInsuringAgencyIncMember" xlink:to="ajg_CoolInsuringAgencyIncMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CoolInsuringAgencyIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cool Insuring Agency, Inc. (CIA) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CoolInsuringAgencyIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cool Insuring Agency Inc [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_HardsenAndAssociatesIncMember" xlink:type="locator" xlink:label="ajg_HardsenAndAssociatesIncMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_HardsenAndAssociatesIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Hardsen and Associates, Inc.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_HardsenAndAssociatesIncMember" xlink:to="ajg_HardsenAndAssociatesIncMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_HardsenAndAssociatesIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Harden &amp; Associates, Inc. (HAI) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_HardsenAndAssociatesIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Hardsen And Associates Inc [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_OtherAcquisitionsMember" xlink:type="locator" xlink:label="ajg_OtherAcquisitionsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_OtherAcquisitionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Other acquisitions.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_OtherAcquisitionsMember" xlink:to="ajg_OtherAcquisitionsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_OtherAcquisitionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Twenty Other Acquisitions [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_OtherAcquisitionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Acquisitions [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Acquisition [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition [Line Items]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Shares Issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:to="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Equity Interests Issued Or Issuable Number Of Shares Issued</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Share Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable" xlink:to="us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Consideration Transferred Equity Interests Issued And Issuable</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash Paid</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireBusinessesGross" xlink:to="us-gaap_PaymentsToAcquireBusinessesGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Payments To Acquire Businesses Gross</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAccruedLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued Liability</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAccruedLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Accrued Liability</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EscrowDeposit" xlink:type="locator" xlink:label="us-gaap_EscrowDeposit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EscrowDeposit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Escrow Deposited</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EscrowDeposit" xlink:to="us-gaap_EscrowDeposit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EscrowDeposit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Escrow Deposit</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedEarnOutPayable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recorded Earnout Payable</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedEarnOutPayable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Earn Out Payable</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionCostOfAcquiredEntityPurchasePriceNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total Recorded Purchase Price</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionCostOfAcquiredEntityPurchasePriceNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Cost Of Acquired Entity Purchase Price Net</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_MaximumPotentialEarnoutPayable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum Potential Earnout Payable</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_MaximumPotentialEarnoutPayable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Maximum Potential Earnout Payable</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessAcquisitionNumberOfEmployeesInAcquiredCompany" xlink:type="locator" xlink:label="ajg_BusinessAcquisitionNumberOfEmployeesInAcquiredCompany" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionNumberOfEmployeesInAcquiredCompany_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business acquisition number of employees in acquired company.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BusinessAcquisitionNumberOfEmployeesInAcquiredCompany" xlink:to="ajg_BusinessAcquisitionNumberOfEmployeesInAcquiredCompany_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessAcquisitionNumberOfOperatingOfficesInAcquiredCompany" xlink:type="locator" xlink:label="ajg_BusinessAcquisitionNumberOfOperatingOfficesInAcquiredCompany" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionNumberOfOperatingOfficesInAcquiredCompany_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business acquisition, number of operating offices in acquired company.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BusinessAcquisitionNumberOfOperatingOfficesInAcquiredCompany" xlink:to="ajg_BusinessAcquisitionNumberOfOperatingOfficesInAcquiredCompany_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TheBollingtonWilsonGroupMember" xlink:type="locator" xlink:label="ajg_TheBollingtonWilsonGroupMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TheBollingtonWilsonGroupMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The Bollington Wilson Group.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TheBollingtonWilsonGroupMember" xlink:to="ajg_TheBollingtonWilsonGroupMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TheBollingtonWilsonGroupMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">The Bollington Wilson Group [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TheBollingtonWilsonGroupMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">The Bollington Wilson Group [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandTwentyAcquisitionsMember" xlink:type="locator" xlink:label="ajg_TwoThousandTwentyAcquisitionsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandTwentyAcquisitionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two thousand twenty acquisitions member.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandTwentyAcquisitionsMember" xlink:to="ajg_TwoThousandTwentyAcquisitionsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandTwentyAcquisitionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2020 Acquisitions [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandTwentyAcquisitionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Twenty Acquisitions [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationTechniqueAxis" xlink:type="locator" xlink:label="us-gaap_ValuationTechniqueAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ValuationTechniqueAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Valuation Approach and Technique</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationTechniqueAxis" xlink:to="us-gaap_ValuationTechniqueAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ValuationTechniqueAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Valuation Technique [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationTechniqueDomain" xlink:type="locator" xlink:label="us-gaap_ValuationTechniqueDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ValuationTechniqueDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Valuation Approach and Technique</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationTechniqueDomain" xlink:to="us-gaap_ValuationTechniqueDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ValuationTechniqueDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Valuation Technique [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MarketApproachValuationTechniqueMember" xlink:type="locator" xlink:label="us-gaap_MarketApproachValuationTechniqueMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MarketApproachValuationTechniqueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Valuation, Market Approach [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MarketApproachValuationTechniqueMember" xlink:to="us-gaap_MarketApproachValuationTechniqueMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MarketApproachValuationTechniqueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Market Approach Valuation Technique [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeApproachValuationTechniqueMember" xlink:type="locator" xlink:label="us-gaap_IncomeApproachValuationTechniqueMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeApproachValuationTechniqueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Valuation, Income Approach [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeApproachValuationTechniqueMember" xlink:to="us-gaap_IncomeApproachValuationTechniqueMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeApproachValuationTechniqueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Approach Valuation Technique [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MeasurementInputTypeAxis" xlink:type="locator" xlink:label="us-gaap_MeasurementInputTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MeasurementInputTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Measurement Input Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputTypeAxis" xlink:to="us-gaap_MeasurementInputTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MeasurementInputTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Input Type [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MeasurementInputTypeDomain" xlink:type="locator" xlink:label="us-gaap_MeasurementInputTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MeasurementInputTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Measurement Input Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MeasurementInputTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Input Type [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MeasurementInputDiscountRateMember" xlink:type="locator" xlink:label="us-gaap_MeasurementInputDiscountRateMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MeasurementInputDiscountRateMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Measurement Input, Discount Rate [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputDiscountRateMember" xlink:to="us-gaap_MeasurementInputDiscountRateMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MeasurementInputDiscountRateMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Input Discount Rate [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:type="locator" xlink:label="us-gaap_StatementBusinessSegmentsAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementBusinessSegmentsAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementBusinessSegmentsAxis" xlink:to="us-gaap_StatementBusinessSegmentsAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementBusinessSegmentsAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Business Segments [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain" xlink:type="locator" xlink:label="us-gaap_SegmentDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SegmentDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentDomain" xlink:to="us-gaap_SegmentDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SegmentDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Segment [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InsuranceBrokerageManagementServicesMember" xlink:type="locator" xlink:label="ajg_InsuranceBrokerageManagementServicesMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_InsuranceBrokerageManagementServicesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Insurance brokerage management services.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InsuranceBrokerageManagementServicesMember" xlink:to="ajg_InsuranceBrokerageManagementServicesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_InsuranceBrokerageManagementServicesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Brokerage Management [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InsuranceBrokerageManagementServicesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Insurance Brokerage Management Services [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandTwentyAcquisitionMember" xlink:type="locator" xlink:label="ajg_TwoThousandTwentyAcquisitionMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandTwentyAcquisitionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two thousand twenty acquisition.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandTwentyAcquisitionMember" xlink:to="ajg_TwoThousandTwentyAcquisitionMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandTwentyAcquisitionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2020 Acquisitions [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandTwentyAcquisitionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Twenty Acquisition [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandNineteenAcquisitionsMember" xlink:type="locator" xlink:label="ajg_TwoThousandNineteenAcquisitionsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandNineteenAcquisitionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two thousand nineteen acquisitions.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandNineteenAcquisitionsMember" xlink:to="ajg_TwoThousandNineteenAcquisitionsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandNineteenAcquisitionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2019 Acquisitions [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandNineteenAcquisitionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Nineteen Acquisitions [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MeasurementInputLongTermRevenueGrowthRateMember" xlink:type="locator" xlink:label="us-gaap_MeasurementInputLongTermRevenueGrowthRateMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MeasurementInputLongTermRevenueGrowthRateMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Measurement Input, Long-term Revenue Growth Rate [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MeasurementInputLongTermRevenueGrowthRateMember" xlink:to="us-gaap_MeasurementInputLongTermRevenueGrowthRateMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MeasurementInputLongTermRevenueGrowthRateMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Input Long Term Revenue Growth Rate [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InsuranceBrokerageAndRiskManagementServicesMember" xlink:type="locator" xlink:label="ajg_InsuranceBrokerageAndRiskManagementServicesMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_InsuranceBrokerageAndRiskManagementServicesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Insurance Brokerage And Risk Management Services [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InsuranceBrokerageAndRiskManagementServicesMember" xlink:to="ajg_InsuranceBrokerageAndRiskManagementServicesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_InsuranceBrokerageAndRiskManagementServicesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Brokerage and Risk Management [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InsuranceBrokerageAndRiskManagementServicesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Insurance Brokerage And Risk Management Services [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessAcquisitionMember" xlink:type="locator" xlink:label="ajg_BusinessAcquisitionMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Acquisition [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BusinessAcquisitionMember" xlink:to="ajg_BusinessAcquisitionMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Acquisition [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BrokerageSegmentMember" xlink:type="locator" xlink:label="ajg_BrokerageSegmentMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_BrokerageSegmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Brokerage Segment Member</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BrokerageSegmentMember" xlink:to="ajg_BrokerageSegmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_BrokerageSegmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Brokerage [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BrokerageSegmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Brokerage Segment [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of voting interest</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:to="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Percentage Of Voting Interests Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Cash consideration</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionNumberOfEmployeesInAcquiredCompany_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of employees in the acquired company</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionNumberOfEmployeesInAcquiredCompany_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Number Of Employees In Acquired Company</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionNumberOfOperatingOfficesInAcquiredCompany_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of operating offices in the acquired company</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionNumberOfOperatingOfficesInAcquiredCompany_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Number Of Operating Offices In Acquired Company</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAccruedLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Accrued liability</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AlternativeInvestmentMeasurementInput" xlink:type="locator" xlink:label="us-gaap_AlternativeInvestmentMeasurementInput" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AlternativeInvestmentMeasurementInput_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Measurement input</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AlternativeInvestmentMeasurementInput" xlink:to="us-gaap_AlternativeInvestmentMeasurementInput_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AlternativeInvestmentMeasurementInput_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Alternative Investment Measurement Input</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessCombinationAggregateEarnoutObligationMaximum" xlink:type="locator" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationMaximum" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationMaximum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination ,Aggregate Earnout Obligation, Maximum</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BusinessCombinationAggregateEarnoutObligationMaximum" xlink:to="ajg_BusinessCombinationAggregateEarnoutObligationMaximum_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessCombinationAggregateEarnoutObligationRecordedMaximum" xlink:type="locator" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationRecordedMaximum" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationRecordedMaximum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination Aggregate Earnout Obligation Recorded Maximum</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BusinessCombinationAggregateEarnoutObligationRecordedMaximum" xlink:to="ajg_BusinessCombinationAggregateEarnoutObligationRecordedMaximum_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCash" xlink:type="locator" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCash" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business combination aggregate earnout obligation expected settlement in cash.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCash" xlink:to="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCash_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCashOrStockAtOption" xlink:type="locator" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCashOrStockAtOption" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCashOrStockAtOption_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business combination aggregate earnout obligation expected settlement in cash or stock at option.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCashOrStockAtOption" xlink:to="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCashOrStockAtOption_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accretion of the discount on acquisition</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed" xlink:to="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Separately Recognized Transactions Additional Disclosures Acquisition Cost Expensed</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income (expense) related to net adjustments to estimated fair value of liability for earnout obligations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:to="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisitions Pro Forma Net Income Loss</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NumberOfBusinessesAcquired" xlink:type="locator" xlink:label="us-gaap_NumberOfBusinessesAcquired" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NumberOfBusinessesAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of companies acquired</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfBusinessesAcquired" xlink:to="us-gaap_NumberOfBusinessesAcquired_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NumberOfBusinessesAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Businesses Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationMaximum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate amount of maximum earnout obligations related to acquisitions</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationMaximum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Aggregate Earnout Obligation Maximum</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationRecordedMaximum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate amount of maximum earnout obligations related to acquisitions, recorded in consolidated balance sheet</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationRecordedMaximum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Aggregate Earnout Obligation Recorded Maximum</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate amount of earnout obligation expected settlement in cash</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Aggregate Earnout Obligation Expected Settlement In Cash</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCashOrStockAtOption_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate amount of earnout obligation expected settlement in cash or stock at option</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAggregateEarnoutObligationExpectedSettlementInCashOrStockAtOption_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Aggregate Earnout Obligation Expected Settlement In Cash Or Stock At Option</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalentsAndRestrictedCash" xlink:type="locator" xlink:label="ajg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalentsAndRestrictedCash" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalentsAndRestrictedCash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business combination recognized identifiable assets acquired and liabilities assumed cash and equivalents and restricted cash.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalentsAndRestrictedCash" xlink:to="ajg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalentsAndRestrictedCash_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessAcquisitionsPurchasePriceAllocationGoodwillAmount" xlink:type="locator" xlink:label="ajg_BusinessAcquisitionsPurchasePriceAllocationGoodwillAmount" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionsPurchasePriceAllocationGoodwillAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Acquisitions Purchase Price Allocation Goodwill Amount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BusinessAcquisitionsPurchasePriceAllocationGoodwillAmount" xlink:to="ajg_BusinessAcquisitionsPurchasePriceAllocationGoodwillAmount_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ExpirationLists" xlink:type="locator" xlink:label="ajg_ExpirationLists" />
    <link:label xml:lang="en-US" xlink:label="ajg_ExpirationLists_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Expiration lists</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ExpirationLists" xlink:to="ajg_ExpirationLists_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessAcquisitionActualRevenueAndPreTaxIncomeLossLineItems" xlink:type="locator" xlink:label="ajg_BusinessAcquisitionActualRevenueAndPreTaxIncomeLossLineItems" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessAcquisitionActualRevenueAndPreTaxIncomeLossLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]</link:label>
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessAcquisitionActualRevenueAndPreTaxIncomeLossTable" xlink:type="locator" xlink:label="ajg_BusinessAcquisitionActualRevenueAndPreTaxIncomeLossTable" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted" xlink:to="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Pro Forma Earnings Per Share Diluted</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BusinessCombinationAnnualizeRevenue" xlink:type="locator" xlink:label="ajg_BusinessCombinationAnnualizeRevenue" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAnnualizeRevenue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination, Annualize Revenue</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BusinessCombinationAnnualizeRevenue" xlink:to="ajg_BusinessCombinationAnnualizeRevenue_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAnnualizeRevenue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveTerseLabel">Annualized revenue of business acquisitions</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BusinessCombinationAnnualizeRevenue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Annualize Revenue</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net earnings</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax" xlink:to="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisitions Pro Forma Income Loss From Continuing Operations Before Changes In Accounting And Extraordinary Items Net Of Tax</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerAssetAndLiabilityAbstract" xlink:type="locator" xlink:label="us-gaap_ContractWithCustomerAssetAndLiabilityAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerAssetAndLiabilityAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Asset And Liability [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerAssetAndLiabilityAbstract" xlink:to="us-gaap_ContractWithCustomerAssetAndLiabilityAbstract_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnbilledContractsReceivable" xlink:type="locator" xlink:label="us-gaap_UnbilledContractsReceivable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnbilledContractsReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unbilled receivables</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnbilledContractsReceivable" xlink:to="us-gaap_UnbilledContractsReceivable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnbilledContractsReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unbilled Contracts Receivable</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostNet" xlink:type="locator" xlink:label="us-gaap_CapitalizedContractCostNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CapitalizedContractCostNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred contract costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalizedContractCostNet" xlink:to="us-gaap_CapitalizedContractCostNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CapitalizedContractCostNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Capitalized Contract Cost Net</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerLiability" xlink:type="locator" xlink:label="us-gaap_ContractWithCustomerLiability" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiability" xlink:to="us-gaap_ContractWithCustomerLiability_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Liability</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ContractWithCustomerLiabilityAdditions" xlink:type="locator" xlink:label="ajg_ContractWithCustomerLiabilityAdditions" />
    <link:label xml:lang="en-US" xlink:label="ajg_ContractWithCustomerLiabilityAdditions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Contract with customer, liability, additions.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ContractWithCustomerLiabilityAdditions" xlink:to="ajg_ContractWithCustomerLiabilityAdditions_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NetChangeInCollectedBillingsAndDepositsReceivedFromCustomers" xlink:type="locator" xlink:label="ajg_NetChangeInCollectedBillingsAndDepositsReceivedFromCustomers" />
    <link:label xml:lang="en-US" xlink:label="ajg_NetChangeInCollectedBillingsAndDepositsReceivedFromCustomers_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Net change in collected billings and deposits received from customers.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NetChangeInCollectedBillingsAndDepositsReceivedFromCustomers" xlink:to="ajg_NetChangeInCollectedBillingsAndDepositsReceivedFromCustomers_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ContractWithCustomerImpactOfChangeInForeignExchangeRates" xlink:type="locator" xlink:label="ajg_ContractWithCustomerImpactOfChangeInForeignExchangeRates" />
    <link:label xml:lang="en-US" xlink:label="ajg_ContractWithCustomerImpactOfChangeInForeignExchangeRates_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Contract with customer impact of change in foreign exchange rates.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ContractWithCustomerImpactOfChangeInForeignExchangeRates" xlink:to="ajg_ContractWithCustomerImpactOfChangeInForeignExchangeRates_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredRevenueDisclosureAbstract" xlink:type="locator" xlink:label="us-gaap_DeferredRevenueDisclosureAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueDisclosureAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue Disclosure [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueDisclosureAbstract" xlink:to="us-gaap_DeferredRevenueDisclosureAbstract_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredRevenueArrangementByTypeTable" xlink:type="locator" xlink:label="us-gaap_DeferredRevenueArrangementByTypeTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueArrangementByTypeTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Revenue Arrangement By Type [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueArrangementByTypeTable" xlink:to="us-gaap_DeferredRevenueArrangementByTypeTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueArrangementByTypeTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue Arrangement By Type [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BrokerageSegmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Brokerage [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RiskManagementSegmentMember" xlink:type="locator" xlink:label="ajg_RiskManagementSegmentMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_RiskManagementSegmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Risk Management Segment Member</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RiskManagementSegmentMember" xlink:to="ajg_RiskManagementSegmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_RiskManagementSegmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Risk Management [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RiskManagementSegmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Risk Management Segment [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredRevenueArrangementLineItems" xlink:type="locator" xlink:label="us-gaap_DeferredRevenueArrangementLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueArrangementLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Revenue Arrangement [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueArrangementLineItems" xlink:to="us-gaap_DeferredRevenueArrangementLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueArrangementLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue Arrangement [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Deferred revenue beginning balance</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ContractWithCustomerLiabilityAdditions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Incremental deferred revenue</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ContractWithCustomerLiabilityAdditions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Liability Additions</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:type="locator" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Revenue recognized during the year included in deferred revenue of prior year</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:to="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Liability Revenue Recognized</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NetChangeInCollectedBillingsAndDepositsReceivedFromCustomers_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net change in collected billings/deposits received from customers</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NetChangeInCollectedBillingsAndDepositsReceivedFromCustomers_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Net Change In Collected Billings And Deposits Received From Customers</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ContractWithCustomerImpactOfChangeInForeignExchangeRates_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Impact of changes in foreign exchange rates</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ContractWithCustomerImpactOfChangeInForeignExchangeRates_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Impact Of Change In Foreign Exchange Rates</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination" xlink:type="locator" xlink:label="us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue recognized from business acquisitions</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination" xlink:to="us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Liability Increase Decrease For Contract Acquired In Business Combination</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Deferred revenue ending balance</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation" xlink:type="locator" xlink:label="us-gaap_RevenueRemainingPerformanceObligation" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueRemainingPerformanceObligation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Remaining performance obligations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligation" xlink:to="us-gaap_RevenueRemainingPerformanceObligation_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueRemainingPerformanceObligation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Revenue Remaining Performance Obligation</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuePerformanceObligationAbstract" xlink:type="locator" xlink:label="us-gaap_RevenuePerformanceObligationAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenuePerformanceObligationAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Revenue Performance Obligation [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenuePerformanceObligationAbstract" xlink:to="us-gaap_RevenuePerformanceObligationAbstract_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:type="locator" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:to="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:type="locator" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:to="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Start Date [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:type="locator" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:to="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueRemainingPerformanceObligation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Expected revenue related to performance obligations</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:type="locator" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Remaining performance obligation, expected timing of satisfaction, period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:to="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostAccumulatedAmortization" xlink:type="locator" xlink:label="us-gaap_CapitalizedContractCostAccumulatedAmortization" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CapitalizedContractCostAccumulatedAmortization_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of deferred contract costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalizedContractCostAccumulatedAmortization" xlink:to="us-gaap_CapitalizedContractCostAccumulatedAmortization_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CapitalizedContractCostAccumulatedAmortization_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Capitalized Contract Cost Accumulated Amortization</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AccruedSupplementalDirectBillAndOtherReceivablesCurrent" xlink:type="locator" xlink:label="ajg_AccruedSupplementalDirectBillAndOtherReceivablesCurrent" />
    <link:label xml:lang="en-US" xlink:label="ajg_AccruedSupplementalDirectBillAndOtherReceivablesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Accrued Supplemental Direct Bill And Other Receivables Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AccruedSupplementalDirectBillAndOtherReceivablesCurrent" xlink:to="ajg_AccruedSupplementalDirectBillAndOtherReceivablesCurrent_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RefinedCoalProductionRelatedReceivablesCurrent" xlink:type="locator" xlink:label="ajg_RefinedCoalProductionRelatedReceivablesCurrent" />
    <link:label xml:lang="en-US" xlink:label="ajg_RefinedCoalProductionRelatedReceivablesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Refined Coal Production Related Receivables Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RefinedCoalProductionRelatedReceivablesCurrent" xlink:to="ajg_RefinedCoalProductionRelatedReceivablesCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccountsReceivableBilledForLongTermContractsOrPrograms_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Premium finance advances and loans</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AccruedSupplementalDirectBillAndOtherReceivablesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued supplemental, direct bill and other receivables</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AccruedSupplementalDirectBillAndOtherReceivablesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Supplemental Direct Bill And Other Receivables Current</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RefinedCoalProductionRelatedReceivablesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Refined coal production related receivables</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RefinedCoalProductionRelatedReceivablesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Refined Coal Production Related Receivables Current</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:type="locator" xlink:label="us-gaap_PrepaidExpenseCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PrepaidExpenseCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prepaid expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseCurrent" xlink:to="us-gaap_PrepaidExpenseCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PrepaidExpenseCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Expense Current</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total other current assets</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ComputerEquipmentGross" xlink:type="locator" xlink:label="ajg_ComputerEquipmentGross" />
    <link:label xml:lang="en-US" xlink:label="ajg_ComputerEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Computer Equipment, Gross</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ComputerEquipmentGross" xlink:to="ajg_ComputerEquipmentGross_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_LandAndBuildingsGross" xlink:type="locator" xlink:label="ajg_LandAndBuildingsGross" />
    <link:label xml:lang="en-US" xlink:label="ajg_LandAndBuildingsGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Land and buildings gross.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_LandAndBuildingsGross" xlink:to="ajg_LandAndBuildingsGross_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PropertyPlantAndEquipmentUsefulLifeAndValuesAbstract" xlink:type="locator" xlink:label="ajg_PropertyPlantAndEquipmentUsefulLifeAndValuesAbstract" />
    <link:label xml:lang="en-US" xlink:label="ajg_PropertyPlantAndEquipmentUsefulLifeAndValuesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Property Plant and Equipment Useful Life and Values [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PropertyPlantAndEquipmentUsefulLifeAndValuesAbstract" xlink:to="ajg_PropertyPlantAndEquipmentUsefulLifeAndValuesAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_PropertyPlantAndEquipmentUsefulLifeAndValuesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Useful Life And Values [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MachineryAndEquipmentGross" xlink:type="locator" xlink:label="us-gaap_MachineryAndEquipmentGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MachineryAndEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Office equipment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MachineryAndEquipmentGross" xlink:to="us-gaap_MachineryAndEquipmentGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MachineryAndEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Machinery And Equipment Gross</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FurnitureAndFixturesGross" xlink:type="locator" xlink:label="us-gaap_FurnitureAndFixturesGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FurnitureAndFixturesGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Furniture and fixtures</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FurnitureAndFixturesGross" xlink:to="us-gaap_FurnitureAndFixturesGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FurnitureAndFixturesGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Furniture And Fixtures Gross</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LeaseholdImprovementsGross" xlink:type="locator" xlink:label="us-gaap_LeaseholdImprovementsGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LeaseholdImprovementsGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Leasehold improvements</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseholdImprovementsGross" xlink:to="us-gaap_LeaseholdImprovementsGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LeaseholdImprovementsGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Leasehold Improvements Gross</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ComputerEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Computer equipment</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ComputerEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Computer Equipment Gross</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_LandAndBuildingsGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Land and buildings - corporate headquarters</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_LandAndBuildingsGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Land And Buildings Gross</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedComputerSoftwareGross" xlink:type="locator" xlink:label="us-gaap_CapitalizedComputerSoftwareGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CapitalizedComputerSoftwareGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Software</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalizedComputerSoftwareGross" xlink:to="us-gaap_CapitalizedComputerSoftwareGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CapitalizedComputerSoftwareGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Capitalized Computer Software Gross</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentOther" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentOther" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentOther_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentOther" xlink:to="us-gaap_PropertyPlantAndEquipmentOther_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentOther_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Other</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConstructionInProgressGross" xlink:type="locator" xlink:label="us-gaap_ConstructionInProgressGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConstructionInProgressGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Work in process</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConstructionInProgressGross" xlink:to="us-gaap_ConstructionInProgressGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConstructionInProgressGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Construction In Progress Gross</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Gross fixed assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentGross" xlink:to="us-gaap_PropertyPlantAndEquipmentGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Gross</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Accumulated depreciation</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Depreciation Depletion And Amortization Property Plant And Equipment</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net fixed assets</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfGoodwillTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfGoodwillTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfGoodwillTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Goodwill [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfGoodwillTable" xlink:to="us-gaap_ScheduleOfGoodwillTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfGoodwillTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Goodwill [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CorporateMember" xlink:type="locator" xlink:label="us-gaap_CorporateMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CorporateMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Corporate [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CorporateMember" xlink:to="us-gaap_CorporateMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CorporateMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Corporate [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis" xlink:type="locator" xlink:label="srt_StatementGeographicalAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_StatementGeographicalAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Geographical</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_StatementGeographicalAxis" xlink:to="srt_StatementGeographicalAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_StatementGeographicalAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Geographical [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:type="locator" xlink:label="srt_SegmentGeographicalDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_SegmentGeographicalDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Geographical</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_SegmentGeographicalDomain" xlink:to="srt_SegmentGeographicalDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_SegmentGeographicalDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Segment Geographical [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:type="locator" xlink:label="country_US" />
    <link:label xml:lang="en-US" xlink:label="country_US_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unites States [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="country_US" xlink:to="country_US_lbl" />
    <link:label xml:lang="en-US" xlink:label="country_US_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">UNITED STATES</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_GB" xlink:type="locator" xlink:label="country_GB" />
    <link:label xml:lang="en-US" xlink:label="country_GB_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">United Kingdom [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="country_GB" xlink:to="country_GB_lbl" />
    <link:label xml:lang="en-US" xlink:label="country_GB_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">UNITED KINGDOM</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_CA" xlink:type="locator" xlink:label="country_CA" />
    <link:label xml:lang="en-US" xlink:label="country_CA_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Canada [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="country_CA" xlink:to="country_CA_lbl" />
    <link:label xml:lang="en-US" xlink:label="country_CA_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">CANADA</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_AU" xlink:type="locator" xlink:label="country_AU" />
    <link:label xml:lang="en-US" xlink:label="country_AU_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Australia [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="country_AU" xlink:to="country_AU_lbl" />
    <link:label xml:lang="en-US" xlink:label="country_AU_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">AUSTRALIA</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_NZ" xlink:type="locator" xlink:label="country_NZ" />
    <link:label xml:lang="en-US" xlink:label="country_NZ_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">New Zealand [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="country_NZ" xlink:to="country_NZ_lbl" />
    <link:label xml:lang="en-US" xlink:label="country_NZ_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">NEW ZEALAND</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_OtherForeignMember" xlink:type="locator" xlink:label="ajg_OtherForeignMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_OtherForeignMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Other Foreign [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_OtherForeignMember" xlink:to="ajg_OtherForeignMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_OtherForeignMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Foreign [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_OtherForeignMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Foreign [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillLineItems" xlink:type="locator" xlink:label="us-gaap_GoodwillLineItems" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillLineItems" xlink:to="us-gaap_GoodwillLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GoodwillLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_Goodwill_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total goodwill - net</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod" xlink:type="locator" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill acquired during the year</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAcquiredDuringPeriod" xlink:to="us-gaap_GoodwillAcquiredDuringPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill Acquired During Period</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments" xlink:type="locator" xlink:label="us-gaap_GoodwillPurchaseAccountingAdjustments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GoodwillPurchaseAccountingAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill adjustments related to appraisals and other acquisition adjustments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillPurchaseAccountingAdjustments" xlink:to="us-gaap_GoodwillPurchaseAccountingAdjustments_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GoodwillPurchaseAccountingAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill Purchase Accounting Adjustments</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit" xlink:type="locator" xlink:label="us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Goodwill written-off related to sales of business</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit" xlink:to="us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill Written Off Related To Sale Of Business Unit</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments" xlink:type="locator" xlink:label="us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign currency translation adjustments during the year</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments" xlink:to="us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill Translation And Purchase Accounting Adjustments</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_Goodwill_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending Balance</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Finite Lived Intangible Assets [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:to="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Finite Lived Intangible Assets [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finite-Lived Intangible Assets [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finite Lived Intangible Assets [Line Items]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortizable intangible assets, gross</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsGross" xlink:to="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finite Lived Intangible Assets Gross</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Accumulated amortization</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finite Lived Intangible Assets Accumulated Amortization</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Amortizable intangible assets, net</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2021</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finite Lived Intangible Assets Amortization Expense Next Twelve Months</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2022</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finite Lived Intangible Assets Amortization Expense Year Two</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finite Lived Intangible Assets Amortization Expense Year Three</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finite Lived Intangible Assets Amortization Expense Year Four</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finite Lived Intangible Assets Amortization Expense Year Five</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Thereafter</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finite Lived Intangible Assets Amortization Expense After Year Five</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DebtLongTermAndShortTermCombinedAmountGross" xlink:type="locator" xlink:label="ajg_DebtLongTermAndShortTermCombinedAmountGross" />
    <link:label xml:lang="en-US" xlink:label="ajg_DebtLongTermAndShortTermCombinedAmountGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt long-term and short-term combined amount gross.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DebtLongTermAndShortTermCombinedAmountGross" xlink:to="ajg_DebtLongTermAndShortTermCombinedAmountGross_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ExtinguishmentOfDebtAxis" xlink:type="locator" xlink:label="us-gaap_ExtinguishmentOfDebtAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ExtinguishmentOfDebtAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Extinguishment of Debt</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ExtinguishmentOfDebtAxis" xlink:to="us-gaap_ExtinguishmentOfDebtAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ExtinguishmentOfDebtAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Extinguishment Of Debt [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ExtinguishmentOfDebtTypeDomain" xlink:type="locator" xlink:label="us-gaap_ExtinguishmentOfDebtTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ExtinguishmentOfDebtTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Extinguishment of Debt, Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ExtinguishmentOfDebtTypeDomain" xlink:to="us-gaap_ExtinguishmentOfDebtTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ExtinguishmentOfDebtTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Extinguishment Of Debt Type [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfThreePointFourEightPercentBalloonDueJuneTwentyFourTwoThousandTwentyMember" xlink:type="locator" xlink:label="ajg_FixedRateOfThreePointFourEightPercentBalloonDueJuneTwentyFourTwoThousandTwentyMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointFourEightPercentBalloonDueJuneTwentyFourTwoThousandTwentyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of three point four eight percent balloon due June twenty four, two thousand twenty.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfThreePointFourEightPercentBalloonDueJuneTwentyFourTwoThousandTwentyMember" xlink:to="ajg_FixedRateOfThreePointFourEightPercentBalloonDueJuneTwentyFourTwoThousandTwentyMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointFourEightPercentBalloonDueJuneTwentyFourTwoThousandTwentyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 3.48%, Balloon Due June 24, 2020 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointFourEightPercentBalloonDueJuneTwentyFourTwoThousandTwentyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Three Point Four Eight Percent Balloon Due June Twenty Four Two Thousand Twenty [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfThreePointNineNinePercentBalloonDueJulyTenTwoThousandTwentyMember" xlink:type="locator" xlink:label="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJulyTenTwoThousandTwentyMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJulyTenTwoThousandTwentyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of three point nine nine percent, balloon due July ten, two thousand twenty.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJulyTenTwoThousandTwentyMember" xlink:to="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJulyTenTwoThousandTwentyMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJulyTenTwoThousandTwentyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 3.99%, Balloon Due July 10, 2020 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJulyTenTwoThousandTwentyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Three Point Nine Nine Percent Balloon Due July Ten Two Thousand Twenty [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFivePointOneEightPercentBalloonDueFebruaryTenTwoThousandTwentyOneMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFivePointOneEightPercentBalloonDueFebruaryTenTwoThousandTwentyOneMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointOneEightPercentBalloonDueFebruaryTenTwoThousandTwentyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed Rate Of Five Point One Eight Percent Balloon Due February Ten Two Thousand Twenty One [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFivePointOneEightPercentBalloonDueFebruaryTenTwoThousandTwentyOneMember" xlink:to="ajg_FixedRateOfFivePointOneEightPercentBalloonDueFebruaryTenTwoThousandTwentyOneMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointOneEightPercentBalloonDueFebruaryTenTwoThousandTwentyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 5.18%, Balloon Due February 10, 2021 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointOneEightPercentBalloonDueFebruaryTenTwoThousandTwentyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Five Point One Eight Percent Balloon Due February Ten Two Thousand Twenty One [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfThreePointSixNinePercentBalloonDueJuneFourteenTwoThousandTwentyTwoMember" xlink:type="locator" xlink:label="ajg_FixedRateOfThreePointSixNinePercentBalloonDueJuneFourteenTwoThousandTwentyTwoMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointSixNinePercentBalloonDueJuneFourteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of three point six nine percent, balloon due June fourteen, two thousand twenty two.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfThreePointSixNinePercentBalloonDueJuneFourteenTwoThousandTwentyTwoMember" xlink:to="ajg_FixedRateOfThreePointSixNinePercentBalloonDueJuneFourteenTwoThousandTwentyTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointSixNinePercentBalloonDueJuneFourteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 3.69%, Balloon Due June 14, 2022 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointSixNinePercentBalloonDueJuneFourteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Three Point Six Nine Percent Balloon Due June Fourteen Two Thousand Twenty Two [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFivePointFourNinePercentBalloonDueFebruaryTenTwoThousandTwentyThreeMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFivePointFourNinePercentBalloonDueFebruaryTenTwoThousandTwentyThreeMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointFourNinePercentBalloonDueFebruaryTenTwoThousandTwentyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of five point four nine percent, balloon due February ten, two thousand twenty three.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFivePointFourNinePercentBalloonDueFebruaryTenTwoThousandTwentyThreeMember" xlink:to="ajg_FixedRateOfFivePointFourNinePercentBalloonDueFebruaryTenTwoThousandTwentyThreeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointFourNinePercentBalloonDueFebruaryTenTwoThousandTwentyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 5.49%, Balloon Due February 10, 2023 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointFourNinePercentBalloonDueFebruaryTenTwoThousandTwentyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Five Point Four Nine Percent Balloon Due February Ten Two Thousand Twenty Three [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointOneThreePercentageBalloonDueJuneTwentyFourTwoThousandTwentyThreeMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointOneThreePercentageBalloonDueJuneTwentyFourTwoThousandTwentyThreeMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneThreePercentageBalloonDueJuneTwentyFourTwoThousandTwentyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed Rate Of Four Point One Three Percentage Balloon Due June Twenty Four Two Thousand Twenty Three [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointOneThreePercentageBalloonDueJuneTwentyFourTwoThousandTwentyThreeMember" xlink:to="ajg_FixedRateOfFourPointOneThreePercentageBalloonDueJuneTwentyFourTwoThousandTwentyThreeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneThreePercentageBalloonDueJuneTwentyFourTwoThousandTwentyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.13%, Balloon Due June 24, 2023 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneThreePercentageBalloonDueJuneTwentyFourTwoThousandTwentyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point One Three Percentage Balloon Due June Twenty Four Two Thousand Twenty Three [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FloatingInterestRateOfOnePointOneSixFivePercentLIBORPlusBalloonDueAugustTwoTwoThousandTwentyThreeMember" xlink:type="locator" xlink:label="ajg_FloatingInterestRateOfOnePointOneSixFivePercentLIBORPlusBalloonDueAugustTwoTwoThousandTwentyThreeMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FloatingInterestRateOfOnePointOneSixFivePercentLIBORPlusBalloonDueAugustTwoTwoThousandTwentyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Floating interest rate of one point one six five percent LIBOR plus balloon due august two two thousand twenty three.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FloatingInterestRateOfOnePointOneSixFivePercentLIBORPlusBalloonDueAugustTwoTwoThousandTwentyThreeMember" xlink:to="ajg_FloatingInterestRateOfOnePointOneSixFivePercentLIBORPlusBalloonDueAugustTwoTwoThousandTwentyThreeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FloatingInterestRateOfOnePointOneSixFivePercentLIBORPlusBalloonDueAugustTwoTwoThousandTwentyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Floating Rate of 1.65% LIBOR Plus Balloon Due August 2, 2023 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FloatingInterestRateOfOnePointOneSixFivePercentLIBORPlusBalloonDueAugustTwoTwoThousandTwentyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Floating Interest Rate Of One Point One Six Five Percent L I B O R Plus Balloon Due August Two Two Thousand Twenty Three [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointSevenTwoPercentBalloonDueFebruaryThirteenTwoThousandTwentyFourMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointSevenTwoPercentBalloonDueFebruaryThirteenTwoThousandTwentyFourMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSevenTwoPercentBalloonDueFebruaryThirteenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed Rate of 4.72%, Balloon due February 13, 2024 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointSevenTwoPercentBalloonDueFebruaryThirteenTwoThousandTwentyFourMember" xlink:to="ajg_FixedRateOfFourPointSevenTwoPercentBalloonDueFebruaryThirteenTwoThousandTwentyFourMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSevenTwoPercentBalloonDueFebruaryThirteenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.72%, Balloon due February 13, 2024 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSevenTwoPercentBalloonDueFebruaryThirteenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Seven Two Percent Balloon Due February Thirteen Two Thousand Twenty Four [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointFiveEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyFourMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointFiveEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyFourMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFiveEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point five eight percent, balloon due February twenty seven, two thousand twenty four.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointFiveEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyFourMember" xlink:to="ajg_FixedRateOfFourPointFiveEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyFourMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFiveEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.58%, Balloon Due February 27, 2024 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFiveEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Five Eight Percent Balloon Due February Twenty Seven Two Thousand Twenty Four [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FloatingInterestRateOfOnePointFourZeroPercentLIBORPlusBalloonDueJuneThirteenTwoThousandTwentyFourMember" xlink:type="locator" xlink:label="ajg_FloatingInterestRateOfOnePointFourZeroPercentLIBORPlusBalloonDueJuneThirteenTwoThousandTwentyFourMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FloatingInterestRateOfOnePointFourZeroPercentLIBORPlusBalloonDueJuneThirteenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Floating interest rate of one point four zero percent LIBOR plus balloon due June thirteen two thousand twenty four.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FloatingInterestRateOfOnePointFourZeroPercentLIBORPlusBalloonDueJuneThirteenTwoThousandTwentyFourMember" xlink:to="ajg_FloatingInterestRateOfOnePointFourZeroPercentLIBORPlusBalloonDueJuneThirteenTwoThousandTwentyFourMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FloatingInterestRateOfOnePointFourZeroPercentLIBORPlusBalloonDueJuneThirteenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Floating Interest Rate of 1.40% LIBOR Plus Balloon Due June 13, 2024 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FloatingInterestRateOfOnePointFourZeroPercentLIBORPlusBalloonDueJuneThirteenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Floating Interest Rate Of One Point Four Zero Percent L I B O R Plus Balloon Due June Thirteen Two Thousand Twenty Four [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointThreeOnePercentBalloonDueJuneTwentyFourTwoThousandTwentyFiveMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointThreeOnePercentBalloonDueJuneTwentyFourTwoThousandTwentyFiveMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeOnePercentBalloonDueJuneTwentyFourTwoThousandTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point three one percent, balloon due June twenty four, two thousand twenty five.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointThreeOnePercentBalloonDueJuneTwentyFourTwoThousandTwentyFiveMember" xlink:to="ajg_FixedRateOfFourPointThreeOnePercentBalloonDueJuneTwentyFourTwoThousandTwentyFiveMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeOnePercentBalloonDueJuneTwentyFourTwoThousandTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.31%, Balloon Due June 24, 2025 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeOnePercentBalloonDueJuneTwentyFourTwoThousandTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Three One Percent Balloon Due June Twenty Four Two Thousand Twenty Five [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointEightFivePercentBalloonDueFebruaryThirteenTwoThousandTwentySixMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointEightFivePercentBalloonDueFebruaryThirteenTwoThousandTwentySixMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointEightFivePercentBalloonDueFebruaryThirteenTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point eight five percent balloon due february thirteen two thousand twenty six.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointEightFivePercentBalloonDueFebruaryThirteenTwoThousandTwentySixMember" xlink:to="ajg_FixedRateOfFourPointEightFivePercentBalloonDueFebruaryThirteenTwoThousandTwentySixMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointEightFivePercentBalloonDueFebruaryThirteenTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.85%, Balloon due February 13, 2026 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointEightFivePercentBalloonDueFebruaryThirteenTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Eight Five Percent Balloon Due February Thirteen Two Thousand Twenty Six [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointSevenThreePercentBalloonDueFebruaryTwentySevenTwoThousandTwentySixMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointSevenThreePercentBalloonDueFebruaryTwentySevenTwoThousandTwentySixMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSevenThreePercentBalloonDueFebruaryTwentySevenTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point seven three, percent balloon due February twenty seven, two thousand twenty six.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointSevenThreePercentBalloonDueFebruaryTwentySevenTwoThousandTwentySixMember" xlink:to="ajg_FixedRateOfFourPointSevenThreePercentBalloonDueFebruaryTwentySevenTwoThousandTwentySixMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSevenThreePercentBalloonDueFebruaryTwentySevenTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.73%, Balloon Due February 27, 2026 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSevenThreePercentBalloonDueFebruaryTwentySevenTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Seven Three Percent Balloon Due February Twenty Seven Two Thousand Twenty Six [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointFourZeroPercentBalloonDueJuneTwoTwoThousandTwentySixMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointFourZeroPercentBalloonDueJuneTwoTwoThousandTwentySixMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourZeroPercentBalloonDueJuneTwoTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point four zero, percent balloon due June two, two thousand twenty six.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointFourZeroPercentBalloonDueJuneTwoTwoThousandTwentySixMember" xlink:to="ajg_FixedRateOfFourPointFourZeroPercentBalloonDueJuneTwoTwoThousandTwentySixMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourZeroPercentBalloonDueJuneTwoTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.40%, Balloon Due June 2, 2026 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourZeroPercentBalloonDueJuneTwoTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Four Zero Percent Balloon Due June Two Two Thousand Twenty Six [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointThreeSixPercentBalloonDueJuneTwentyFourTwoThousandTwentySixMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointThreeSixPercentBalloonDueJuneTwentyFourTwoThousandTwentySixMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeSixPercentBalloonDueJuneTwentyFourTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed Rate Of Four Point Three Six Percent Balloon Due June Twenty Four Two Thousand Twenty Six [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointThreeSixPercentBalloonDueJuneTwentyFourTwoThousandTwentySixMember" xlink:to="ajg_FixedRateOfFourPointThreeSixPercentBalloonDueJuneTwentyFourTwoThousandTwentySixMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeSixPercentBalloonDueJuneTwentyFourTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.36%, Balloon Due June 24, 2026 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeSixPercentBalloonDueJuneTwentyFourTwoThousandTwentySixMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Three Six Percent Balloon Due June Twenty Four Two Thousand Twenty Six [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfThreePointSevenFivePercentBalloonDueJanuaryThirtyTwoThousandTwentySevenMember" xlink:type="locator" xlink:label="ajg_FixedRateOfThreePointSevenFivePercentBalloonDueJanuaryThirtyTwoThousandTwentySevenMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointSevenFivePercentBalloonDueJanuaryThirtyTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed Rate Of Three Point Seven Five Percent Balloon Due January Thirty Two Thousand Twenty Seven [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfThreePointSevenFivePercentBalloonDueJanuaryThirtyTwoThousandTwentySevenMember" xlink:to="ajg_FixedRateOfThreePointSevenFivePercentBalloonDueJanuaryThirtyTwoThousandTwentySevenMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointSevenFivePercentBalloonDueJanuaryThirtyTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 3.75%, Balloon Due January 30, 2027 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointSevenFivePercentBalloonDueJanuaryThirtyTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Three Point Seven Five Percent Balloon Due January Thirty Two Thousand Twenty Seven [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJuneTwentySevenTwoThousandTwentySevenMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJuneTwentySevenTwoThousandTwentySevenMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJuneTwentySevenTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point zero nine percent, balloon due June twenty seven, two thousand twenty seven.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJuneTwentySevenTwoThousandTwentySevenMember" xlink:to="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJuneTwentySevenTwoThousandTwentySevenMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJuneTwentySevenTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.09%, Balloon Due June 27, 2027 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJuneTwentySevenTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Zero Nine Percent Balloon Due June Twenty Seven Two Thousand Twenty Seven [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointZeroNinePercentBalloonDueAugustTwoTwoThousandTwentySevenMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueAugustTwoTwoThousandTwentySevenMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueAugustTwoTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point zero nine percent, balloon due August two, two thousand twenty seven.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueAugustTwoTwoThousandTwentySevenMember" xlink:to="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueAugustTwoTwoThousandTwentySevenMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueAugustTwoTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.09%, Balloon Due August 2, 2027 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueAugustTwoTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Zero Nine Percent Balloon Due August Two Two Thousand Twenty Seven [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointOneFourPercentBalloonDueAugustFourTwoThousandTwentySevenMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointOneFourPercentBalloonDueAugustFourTwoThousandTwentySevenMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneFourPercentBalloonDueAugustFourTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point one four percent, balloon due August four, two thousand twenty seven.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointOneFourPercentBalloonDueAugustFourTwoThousandTwentySevenMember" xlink:to="ajg_FixedRateOfFourPointOneFourPercentBalloonDueAugustFourTwoThousandTwentySevenMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneFourPercentBalloonDueAugustFourTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.14%, Balloon Due August 4, 2027 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneFourPercentBalloonDueAugustFourTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point One Four Percent Balloon Due August Four Two Thousand Twenty Seven [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfThreePointFourSixPercentageBalloonDueDecemberOneTwoThousandTwentySevenMember" xlink:type="locator" xlink:label="ajg_FixedRateOfThreePointFourSixPercentageBalloonDueDecemberOneTwoThousandTwentySevenMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointFourSixPercentageBalloonDueDecemberOneTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of three point four six percentage, balloon due December one, two thousand twenty seven.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfThreePointFourSixPercentageBalloonDueDecemberOneTwoThousandTwentySevenMember" xlink:to="ajg_FixedRateOfThreePointFourSixPercentageBalloonDueDecemberOneTwoThousandTwentySevenMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointFourSixPercentageBalloonDueDecemberOneTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 3.46%, Balloon Due December 1, 2027 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointFourSixPercentageBalloonDueDecemberOneTwoThousandTwentySevenMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Three Point Four Six Percentage Balloon Due December One Two Thousand Twenty Seven [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointFiveFivePercentBalloonDueJuneTwoTwoThousandTwentyEightMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointFiveFivePercentBalloonDueJuneTwoTwoThousandTwentyEightMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFiveFivePercentBalloonDueJuneTwoTwoThousandTwentyEightMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point five five, percent balloon due June two, two thousand twenty eight.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointFiveFivePercentBalloonDueJuneTwoTwoThousandTwentyEightMember" xlink:to="ajg_FixedRateOfFourPointFiveFivePercentBalloonDueJuneTwoTwoThousandTwentyEightMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFiveFivePercentBalloonDueJuneTwoTwoThousandTwentyEightMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.55%, Balloon Due June 2, 2028 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFiveFivePercentBalloonDueJuneTwoTwoThousandTwentyEightMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Five Five Percent Balloon Due June Two Two Thousand Twenty Eight [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneThirteenTwoThousandTwentyEightMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneThirteenTwoThousandTwentyEightMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneThirteenTwoThousandTwentyEightMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point three four percent balloon due June thirteen two thousand twenty eight.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneThirteenTwoThousandTwentyEightMember" xlink:to="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneThirteenTwoThousandTwentyEightMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneThirteenTwoThousandTwentyEightMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.34%, Balloon due June 13, 2028 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneThirteenTwoThousandTwentyEightMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Three Four Percent Balloon Due June Thirteen Two Thousand Twenty Eight [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFivePointZeroFourPercentageBalloonDueFebruaryThirteenTwoThousandTwentyNineMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFivePointZeroFourPercentageBalloonDueFebruaryThirteenTwoThousandTwentyNineMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointZeroFourPercentageBalloonDueFebruaryThirteenTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of five point zero four percentage balloon due february thirteen two thousand twenty nine.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFivePointZeroFourPercentageBalloonDueFebruaryThirteenTwoThousandTwentyNineMember" xlink:to="ajg_FixedRateOfFivePointZeroFourPercentageBalloonDueFebruaryThirteenTwoThousandTwentyNineMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointZeroFourPercentageBalloonDueFebruaryThirteenTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 5.04%, Balloon due February 13, 2029 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointZeroFourPercentageBalloonDueFebruaryThirteenTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Five Point Zero Four Percentage Balloon Due February Thirteen Two Thousand Twenty Nine [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointNineEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyNineMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointNineEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyNineMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointNineEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point nine eight percent, balloon due February twenty seven, two thousand twenty nine.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointNineEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyNineMember" xlink:to="ajg_FixedRateOfFourPointNineEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyNineMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointNineEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.98%, Balloon Due February 27, 2029 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointNineEightPercentBalloonDueFebruaryTwentySevenTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Nine Eight Percent Balloon Due February Twenty Seven Two Thousand Twenty Nine [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointOneNinePercentBalloonDueJuneTwentySevenTwoThousandTwentyNineMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointOneNinePercentBalloonDueJuneTwentySevenTwoThousandTwentyNineMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneNinePercentBalloonDueJuneTwentySevenTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point one nine percent, balloon due June twenty seven, two thousand twenty nine.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointOneNinePercentBalloonDueJuneTwentySevenTwoThousandTwentyNineMember" xlink:to="ajg_FixedRateOfFourPointOneNinePercentBalloonDueJuneTwentySevenTwoThousandTwentyNineMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneNinePercentBalloonDueJuneTwentySevenTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.19%, Balloon Due June 27, 2029 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneNinePercentBalloonDueJuneTwentySevenTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point One Nine Percent Balloon Due June Twenty Seven Two Thousand Twenty Nine [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointOneNinePercentBalloonDueAugustTwoTwoThousandTwentyNineMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointOneNinePercentBalloonDueAugustTwoTwoThousandTwentyNineMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneNinePercentBalloonDueAugustTwoTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point one nine percent, balloon due August two, two thousand twenty nine.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointOneNinePercentBalloonDueAugustTwoTwoThousandTwentyNineMember" xlink:to="ajg_FixedRateOfFourPointOneNinePercentBalloonDueAugustTwoTwoThousandTwentyNineMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneNinePercentBalloonDueAugustTwoTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.19%, Balloon Due August 2, 2029 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointOneNinePercentBalloonDueAugustTwoTwoThousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point One Nine Percent Balloon Due August Two Two Thousand Twenty Nine [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfThreePointFourEightPercentBalloonDueDecemberTwoTwothousandTwentyNineMember" xlink:type="locator" xlink:label="ajg_FixedRateOfThreePointFourEightPercentBalloonDueDecemberTwoTwothousandTwentyNineMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointFourEightPercentBalloonDueDecemberTwoTwothousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed Rate Of Three Point Four Eight Percent Balloon Due December Two Two thousand Twenty Nine</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfThreePointFourEightPercentBalloonDueDecemberTwoTwothousandTwentyNineMember" xlink:to="ajg_FixedRateOfThreePointFourEightPercentBalloonDueDecemberTwoTwothousandTwentyNineMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointFourEightPercentBalloonDueDecemberTwoTwothousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 3.48%, Balloon Due December 2, 2029 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointFourEightPercentBalloonDueDecemberTwoTwothousandTwentyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Three Point Four Eight Percent Balloon Due December Two Twothousand Twenty Nine [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfThreePointNineNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyMember" xlink:type="locator" xlink:label="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed Rate Of Three Point Nine Nine Percent Balloon Due January Thirty Two Thousand Thirty [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyMember" xlink:to="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 3.99%, Balloon Due January 30, 2030 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfThreePointNineNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Three Point Nine Nine Percent Balloon Due January Thirty Two Thousand Thirty [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointFourFourPercentBalloonDueJuneThirteenTwoThousandThirtyMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointFourFourPercentBalloonDueJuneThirteenTwoThousandThirtyMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourFourPercentBalloonDueJuneThirteenTwoThousandThirtyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point four four percent balloon due June thirteen two thousand thirty.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointFourFourPercentBalloonDueJuneThirteenTwoThousandThirtyMember" xlink:to="ajg_FixedRateOfFourPointFourFourPercentBalloonDueJuneThirteenTwoThousandThirtyMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourFourPercentBalloonDueJuneThirteenTwoThousandThirtyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.44%, Balloon Due June 13, 2030 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourFourPercentBalloonDueJuneThirteenTwoThousandThirtyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Four Four Percent Balloon Due June Thirteen Two Thousand Thirty [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFivePointOneFourPercentBalloonDueMarchThirteenTwoThousandThirtyOneMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFivePointOneFourPercentBalloonDueMarchThirteenTwoThousandThirtyOneMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointOneFourPercentBalloonDueMarchThirteenTwoThousandThirtyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of five point one four percent balloon due march thirteen two thousand thirty one.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFivePointOneFourPercentBalloonDueMarchThirteenTwoThousandThirtyOneMember" xlink:to="ajg_FixedRateOfFivePointOneFourPercentBalloonDueMarchThirteenTwoThousandThirtyOneMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointOneFourPercentBalloonDueMarchThirteenTwoThousandThirtyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 5.14%, Balloon due March 13, 2031 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointOneFourPercentBalloonDueMarchThirteenTwoThousandThirtyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Five Point One Four Percent Balloon Due March Thirteen Two Thousand Thirty One [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointSevenZeroPercentBalloonDueJuneTwoTwoThousandThirtyOneMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointSevenZeroPercentBalloonDueJuneTwoTwoThousandThirtyOneMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSevenZeroPercentBalloonDueJuneTwoTwoThousandThirtyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point seven zero percent, balloon due June two, two thousand thirty one.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointSevenZeroPercentBalloonDueJuneTwoTwoThousandThirtyOneMember" xlink:to="ajg_FixedRateOfFourPointSevenZeroPercentBalloonDueJuneTwoTwoThousandThirtyOneMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSevenZeroPercentBalloonDueJuneTwoTwoThousandThirtyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.70%, Balloon Due June 2, 2031 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSevenZeroPercentBalloonDueJuneTwoTwoThousandThirtyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Seven Zero Percent Balloon Due June Two Two Thousand Thirty One [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyTwoMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyTwoMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed Rate Of Four Point Zero Nine Percent Balloon Due January Thirty Two Thousand Thirty Two [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyTwoMember" xlink:to="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.09%, Balloon Due January 30, 2032 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointZeroNinePercentBalloonDueJanuaryThirtyTwoThousandThirtyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Zero Nine Percent Balloon Due January Thirty Two Thousand Thirty Two [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneTwentySevenTwoThousandThirtyTwoMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneTwentySevenTwoThousandThirtyTwoMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneTwentySevenTwoThousandThirtyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point three four percent, balloon due June twenty seven, two thousand thirty two.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneTwentySevenTwoThousandThirtyTwoMember" xlink:to="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneTwentySevenTwoThousandThirtyTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneTwentySevenTwoThousandThirtyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.34%, Balloon Due June 27, 2032 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueJuneTwentySevenTwoThousandThirtyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Three Four Percent Balloon Due June Twenty Seven Two Thousand Thirty Two [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointThreeFourPercentBalloonDueAugustTwoTwoThousandThirtyTwoMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueAugustTwoTwoThousandThirtyTwoMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueAugustTwoTwoThousandThirtyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point three four percent, balloon due August two, two thousand thirty two.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueAugustTwoTwoThousandThirtyTwoMember" xlink:to="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueAugustTwoTwoThousandThirtyTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueAugustTwoTwoThousandThirtyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.34%, Balloon Due August 2, 2032 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointThreeFourPercentBalloonDueAugustTwoTwoThousandThirtyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Three Four Percent Balloon Due August Two Two Thousand Thirty Two [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointFiveNinePercentBalloonDueJuneThirteenTwoThousandThirtyThreeMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointFiveNinePercentBalloonDueJuneThirteenTwoThousandThirtyThreeMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFiveNinePercentBalloonDueJuneThirteenTwoThousandThirtyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point five nine percent balloon due June thirteen two thousand thirty three.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointFiveNinePercentBalloonDueJuneThirteenTwoThousandThirtyThreeMember" xlink:to="ajg_FixedRateOfFourPointFiveNinePercentBalloonDueJuneThirteenTwoThousandThirtyThreeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFiveNinePercentBalloonDueJuneThirteenTwoThousandThirtyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.59%, Balloon due June 13, 2033 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFiveNinePercentBalloonDueJuneThirteenTwoThousandThirtyThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Five Nine Percent Balloon Due June Thirteen Two Thousand Thirty Three [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFivePointTwoNinePercentBalloonDueMarchThirteenTwoThousandThirtyFourMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFivePointTwoNinePercentBalloonDueMarchThirteenTwoThousandThirtyFourMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointTwoNinePercentBalloonDueMarchThirteenTwoThousandThirtyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of five point two nine percent balloon due march thirteen two thousand thirty four.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFivePointTwoNinePercentBalloonDueMarchThirteenTwoThousandThirtyFourMember" xlink:to="ajg_FixedRateOfFivePointTwoNinePercentBalloonDueMarchThirteenTwoThousandThirtyFourMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointTwoNinePercentBalloonDueMarchThirteenTwoThousandThirtyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 5.29%, balloon due March 13, 2034 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointTwoNinePercentBalloonDueMarchThirteenTwoThousandThirtyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Five Point Two Nine Percent Balloon Due March Thirteen Two Thousand Thirty Four [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointFourEightPercentBalloonDueJuneTwelveTwoThousandThirtyFourMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointFourEightPercentBalloonDueJuneTwelveTwoThousandThirtyFourMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourEightPercentBalloonDueJuneTwelveTwoThousandThirtyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point four eight percent balloon due june twelve two thousand thirty four.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointFourEightPercentBalloonDueJuneTwelveTwoThousandThirtyFourMember" xlink:to="ajg_FixedRateOfFourPointFourEightPercentBalloonDueJuneTwelveTwoThousandThirtyFourMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourEightPercentBalloonDueJuneTwelveTwoThousandThirtyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.48%, Balloon Due June 12, 2034 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourEightPercentBalloonDueJuneTwelveTwoThousandThirtyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Four Eight Percent Balloon Due June Twelve Two Thousand Thirty Four [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointTwoFourPercentBalloonDueJanuaryThirtyTwoThousandThirtyFiveMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointTwoFourPercentBalloonDueJanuaryThirtyTwoThousandThirtyFiveMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointTwoFourPercentBalloonDueJanuaryThirtyTwoThousandThirtyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed Rate Of Four Point Two Four Percent Balloon Due January Thirty Two Thousand Thirty Five [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointTwoFourPercentBalloonDueJanuaryThirtyTwoThousandThirtyFiveMember" xlink:to="ajg_FixedRateOfFourPointTwoFourPercentBalloonDueJanuaryThirtyTwoThousandThirtyFiveMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointTwoFourPercentBalloonDueJanuaryThirtyTwoThousandThirtyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.24%, Balloon Due January 30, 2035 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointTwoFourPercentBalloonDueJanuaryThirtyTwoThousandThirtyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Two Four Percent Balloon Due January Thirty Two Thousand Thirty Five [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointSixNinePercentBalloonDueJuneThirteenTwoThousandThirtyEightMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointSixNinePercentBalloonDueJuneThirteenTwoThousandThirtyEightMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSixNinePercentBalloonDueJuneThirteenTwoThousandThirtyEightMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of four point six nine percent balloon due June thirteen two thousand thirty eight.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointSixNinePercentBalloonDueJuneThirteenTwoThousandThirtyEightMember" xlink:to="ajg_FixedRateOfFourPointSixNinePercentBalloonDueJuneThirteenTwoThousandThirtyEightMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSixNinePercentBalloonDueJuneThirteenTwoThousandThirtyEightMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.69%, Balloon Due June 13, 2038 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointSixNinePercentBalloonDueJuneThirteenTwoThousandThirtyEightMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Six Nine Percent Balloon Due June Thirteen Two Thousand Thirty Eight [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFivePointFourFivePercentBalloonDueMarchThirteenTwoThousandThirtyNineMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFivePointFourFivePercentBalloonDueMarchThirteenTwoThousandThirtyNineMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointFourFivePercentBalloonDueMarchThirteenTwoThousandThirtyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate of five point four five percent balloon due march thirteen two thousand thirty nine.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFivePointFourFivePercentBalloonDueMarchThirteenTwoThousandThirtyNineMember" xlink:to="ajg_FixedRateOfFivePointFourFivePercentBalloonDueMarchThirteenTwoThousandThirtyNineMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointFourFivePercentBalloonDueMarchThirteenTwoThousandThirtyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 5.45%, balloon due March 13, 2039 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFivePointFourFivePercentBalloonDueMarchThirteenTwoThousandThirtyNineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Five Point Four Five Percent Balloon Due March Thirteen Two Thousand Thirty Nine [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOfFourPointFourNinePercentBalloonDueJanuaryThirtyTwoThousandFortyMember" xlink:type="locator" xlink:label="ajg_FixedRateOfFourPointFourNinePercentBalloonDueJanuaryThirtyTwoThousandFortyMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourNinePercentBalloonDueJanuaryThirtyTwoThousandFortyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed Rate Of Four Point Four Nine Percent Balloon Due January Thirty Two Thousand Forty [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOfFourPointFourNinePercentBalloonDueJanuaryThirtyTwoThousandFortyMember" xlink:to="ajg_FixedRateOfFourPointFourNinePercentBalloonDueJanuaryThirtyTwoThousandFortyMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourNinePercentBalloonDueJanuaryThirtyTwoThousandFortyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate of 4.49%, Balloon Due January 30, 2040 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOfFourPointFourNinePercentBalloonDueJanuaryThirtyTwoThousandFortyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Of Four Point Four Nine Percent Balloon Due January Thirty Two Thousand Forty [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PrimeOrLiborPlusUpToOnePointFourFivePercentExpiresJuneSevenTwoThousandTwentyFourMember" xlink:type="locator" xlink:label="ajg_PrimeOrLiborPlusUpToOnePointFourFivePercentExpiresJuneSevenTwoThousandTwentyFourMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_PrimeOrLiborPlusUpToOnePointFourFivePercentExpiresJuneSevenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Prime or LIBOR plus up to one point four five percent expires June seven two thousand twenty four.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PrimeOrLiborPlusUpToOnePointFourFivePercentExpiresJuneSevenTwoThousandTwentyFourMember" xlink:to="ajg_PrimeOrLiborPlusUpToOnePointFourFivePercentExpiresJuneSevenTwoThousandTwentyFourMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_PrimeOrLiborPlusUpToOnePointFourFivePercentExpiresJuneSevenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prime or LIBOR Plus up to 1.45%, Expires June 7, 2024 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PrimeOrLiborPlusUpToOnePointFourFivePercentExpiresJuneSevenTwoThousandTwentyFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Prime Or Libor Plus Up To One Point Four Five Percent Expires June Seven Two Thousand Twenty Four [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InterbankRatePlusOnePointFourZeroZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" xlink:type="locator" xlink:label="ajg_InterbankRatePlusOnePointFourZeroZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusOnePointFourZeroZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interbank rate plus one point four zero zero percent expires September fifteen two thousand twenty two.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InterbankRatePlusOnePointFourZeroZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" xlink:to="ajg_InterbankRatePlusOnePointFourZeroZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusOnePointFourZeroZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interbank Rates Plus 1.400% Expires September 15, 2022 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusOnePointFourZeroZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interbank Rate Plus One Point Four Zero Zero Percent Expires September Fifteen Two Thousand Twenty Two [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InterbankRatePlusOnePointSevenFiveZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" xlink:type="locator" xlink:label="ajg_InterbankRatePlusOnePointSevenFiveZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusOnePointSevenFiveZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interbank rate plus one point seven five zero percent expires September fifteen two thousand twenty two</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InterbankRatePlusOnePointSevenFiveZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" xlink:to="ajg_InterbankRatePlusOnePointSevenFiveZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusOnePointSevenFiveZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interbank Rates Plus 1.750% Expires September 15, 2022 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusOnePointSevenFiveZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interbank Rate Plus One Point Seven Five Zero Percent Expires September Fifteen Two Thousand Twenty Two [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InterbankRatePlusZeroPointSevenThreeZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" xlink:type="locator" xlink:label="ajg_InterbankRatePlusZeroPointSevenThreeZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusZeroPointSevenThreeZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interbank rate plus zero point seven three zero percent expires September fifteen two thousand twenty two.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InterbankRatePlusZeroPointSevenThreeZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" xlink:to="ajg_InterbankRatePlusZeroPointSevenThreeZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusZeroPointSevenThreeZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interbank Rates Plus 0.730% Expires September 15, 2022 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusZeroPointSevenThreeZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interbank Rate Plus Zero Point Seven Three Zero Percent Expires September Fifteen Two Thousand Twenty Two [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InterbankRatePlusZeroPointNineFourZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" xlink:type="locator" xlink:label="ajg_InterbankRatePlusZeroPointNineFourZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusZeroPointNineFourZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interbank rate plus zero point nine four zero percent expires September fifteen two thousand twenty two.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InterbankRatePlusZeroPointNineFourZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember" xlink:to="ajg_InterbankRatePlusZeroPointNineFourZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusZeroPointNineFourZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interbank Rates Plus 0.940% Expires September 15, 2022 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatePlusZeroPointNineFourZeroPercentExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interbank Rate Plus Zero Point Nine Four Zero Percent Expires September Fifteen Two Thousand Twenty Two [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InterbankRatesExpiresSeptemberFifteenTwoThousandTwentyTwoMember" xlink:type="locator" xlink:label="ajg_InterbankRatesExpiresSeptemberFifteenTwoThousandTwentyTwoMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatesExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interbank rates expires September fifteen two thousand twenty two.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InterbankRatesExpiresSeptemberFifteenTwoThousandTwentyTwoMember" xlink:to="ajg_InterbankRatesExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatesExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interbank Rates Expires September 15, 2022 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InterbankRatesExpiresSeptemberFifteenTwoThousandTwentyTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interbank Rates Expires September Fifteen Two Thousand Twenty Two [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityAxis" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lender Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityAxis" xlink:to="us-gaap_LineOfCreditFacilityAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityLenderDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityLenderDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Line of Credit Facility, Lender</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityLenderDomain" xlink:to="us-gaap_LineOfCreditFacilityLenderDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityLenderDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Lender [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NotePurchaseAgreementMember" xlink:type="locator" xlink:label="ajg_NotePurchaseAgreementMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_NotePurchaseAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Note Purchase Agreement [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NotePurchaseAgreementMember" xlink:to="ajg_NotePurchaseAgreementMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_NotePurchaseAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Note Purchase Agreements [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NotePurchaseAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Note Purchase Agreement [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UnsecuredMulticurrencyCreditAgreementMember" xlink:type="locator" xlink:label="ajg_UnsecuredMulticurrencyCreditAgreementMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_UnsecuredMulticurrencyCreditAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Unsecured Multicurrency Credit Agreement [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UnsecuredMulticurrencyCreditAgreementMember" xlink:to="ajg_UnsecuredMulticurrencyCreditAgreementMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_UnsecuredMulticurrencyCreditAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Multi Currency Credit Agreement [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UnsecuredMulticurrencyCreditAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unsecured Multicurrency Credit Agreement [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AudDenominatedTrancheMember" xlink:type="locator" xlink:label="ajg_AudDenominatedTrancheMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_AudDenominatedTrancheMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Aud Denominated Tranche [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AudDenominatedTrancheMember" xlink:to="ajg_AudDenominatedTrancheMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_AudDenominatedTrancheMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">AUD Denominated Tranche [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AudDenominatedTrancheMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Aud Denominated Tranche [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NzdDenominatedTrancheMember" xlink:type="locator" xlink:label="ajg_NzdDenominatedTrancheMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_NzdDenominatedTrancheMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">NZD Denominated Tranche [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NzdDenominatedTrancheMember" xlink:to="ajg_NzdDenominatedTrancheMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_NzdDenominatedTrancheMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">NZD Denominated Tranche [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NzdDenominatedTrancheMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Nzd Denominated Tranche [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentNameDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument, Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="us-gaap_DebtInstrumentNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Name [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FacilityBMember" xlink:type="locator" xlink:label="ajg_FacilityBMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FacilityBMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Facility B [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FacilityBMember" xlink:to="ajg_FacilityBMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FacilityBMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Facility B [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FacilityBMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Facility B [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FacilityCAndFacilityDMember" xlink:type="locator" xlink:label="ajg_FacilityCAndFacilityDMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FacilityCAndFacilityDMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Facility C And Facility D</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FacilityCAndFacilityDMember" xlink:to="ajg_FacilityCAndFacilityDMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FacilityCAndFacilityDMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Facility C and D [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FacilityCAndFacilityDMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Facility C And Facility D [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancialInstrumentAxis" xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinancialInstrumentAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financial Instrument</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_FinancialInstrumentAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinancialInstrumentAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Financial Instrument [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financial Instruments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Transfers And Servicing Of Financial Instruments Types Of Financial Instruments [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PremiumFinancingDebtFacilityMember" xlink:type="locator" xlink:label="ajg_PremiumFinancingDebtFacilityMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_PremiumFinancingDebtFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Premium Financing Debt Facility [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PremiumFinancingDebtFacilityMember" xlink:to="ajg_PremiumFinancingDebtFacilityMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_PremiumFinancingDebtFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Premium Financing Debt Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PremiumFinancingDebtFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Premium Financing Debt Facility [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DebtLongTermAndShortTermCombinedAmountGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Semi-annual payments of interest</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DebtLongTermAndShortTermCombinedAmountGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Long Term And Short Term Combined Amount Gross</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnamortizedDebtIssuanceExpense" xlink:type="locator" xlink:label="us-gaap_UnamortizedDebtIssuanceExpense" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnamortizedDebtIssuanceExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Less unamortized debt acquisition costs on Note Purchase Agreements</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnamortizedDebtIssuanceExpense" xlink:to="us-gaap_UnamortizedDebtIssuanceExpense_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnamortizedDebtIssuanceExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unamortized Debt Issuance Expense</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtLongtermAndShorttermCombinedAmount" xlink:type="locator" xlink:label="us-gaap_DebtLongtermAndShorttermCombinedAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtLongtermAndShorttermCombinedAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Semi-annual payments of interest, Net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtLongtermAndShorttermCombinedAmount" xlink:to="us-gaap_DebtLongtermAndShorttermCombinedAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtLongtermAndShorttermCombinedAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Longterm And Shortterm Combined Amount</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DebtInstrumentPrepaymentDate" xlink:type="locator" xlink:label="ajg_DebtInstrumentPrepaymentDate" />
    <link:label xml:lang="en-US" xlink:label="ajg_DebtInstrumentPrepaymentDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt instrument prepayment date.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DebtInstrumentPrepaymentDate" xlink:to="ajg_DebtInstrumentPrepaymentDate_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CreditAgreementMember" xlink:type="locator" xlink:label="ajg_CreditAgreementMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Credit Agreement [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CreditAgreementMember" xlink:to="ajg_CreditAgreementMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Agreement [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CreditAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Credit Agreement [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Periodic Payment of Interest</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Interest Rate Stated Percentage</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentMaturityDate" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentMaturityDate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Periodic payments of interest and principal, expiry date</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentMaturityDate" xlink:to="us-gaap_DebtInstrumentMaturityDate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Maturity Date</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Quarterly payments of interest rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:to="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Basis Spread On Variable Rate1</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentDescriptionOfVariableRateBasis" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Quarterly payments of interest, description</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis" xlink:to="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Description Of Variable Rate Basis</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DebtInstrumentPrepaymentDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, prepayment date</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DebtInstrumentPrepaymentDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Prepayment Date</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:type="locator" xlink:label="us-gaap_LongtermDebtTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongtermDebtTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term Debt, Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongtermDebtTypeAxis" xlink:to="us-gaap_LongtermDebtTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongtermDebtTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Longterm Debt Type [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:type="locator" xlink:label="us-gaap_LongtermDebtTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongtermDebtTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term Debt, Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="us-gaap_LongtermDebtTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongtermDebtTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Longterm Debt Type [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_SeniorUnsecuredNoteMember" xlink:type="locator" xlink:label="ajg_SeniorUnsecuredNoteMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_SeniorUnsecuredNoteMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Senior unsecured notes.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_SeniorUnsecuredNoteMember" xlink:to="ajg_SeniorUnsecuredNoteMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_SeniorUnsecuredNoteMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Senior Unsecured Notes [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_SeniorUnsecuredNoteMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Senior Unsecured Note [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateSeniorUnsecuredNotesMember" xlink:type="locator" xlink:label="ajg_FixedRateSeniorUnsecuredNotesMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateSeniorUnsecuredNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed Rate Senior Unsecured Notes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateSeniorUnsecuredNotesMember" xlink:to="ajg_FixedRateSeniorUnsecuredNotesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateSeniorUnsecuredNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Rate Senior Unsecured Notes [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateSeniorUnsecuredNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Senior Unsecured Notes [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UnsecuredNotesMember" xlink:type="locator" xlink:label="ajg_UnsecuredNotesMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_UnsecuredNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Unsecured Notes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UnsecuredNotesMember" xlink:to="ajg_UnsecuredNotesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_UnsecuredNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unsecured Notes [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UnsecuredNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unsecured Notes [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:type="locator" xlink:label="us-gaap_SubsidiarySaleOfStockAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Subsidiary Sale Of Stock [Axis]</link:label>
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfFinancialInstitutionsEnteredInUnsecuredMulticurrencyCreditAgreement" xlink:type="locator" xlink:label="ajg_NumberOfFinancialInstitutionsEnteredInUnsecuredMulticurrencyCreditAgreement" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfFinancialInstitutionsEnteredInUnsecuredMulticurrencyCreditAgreement_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of financial institutions entered in unsecured multicurrency credit agreement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfFinancialInstitutionsEnteredInUnsecuredMulticurrencyCreditAgreement" xlink:to="ajg_NumberOfFinancialInstitutionsEnteredInUnsecuredMulticurrencyCreditAgreement_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:type="locator" xlink:label="us-gaap_InvestmentTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentTypeAxis" xlink:to="us-gaap_InvestmentTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investment Type [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:type="locator" xlink:label="us-gaap_InvestmentTypeCategorizationMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentTypeCategorizationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="us-gaap_InvestmentTypeCategorizationMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentTypeCategorizationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investment Type Categorization [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StandbyLettersOfCreditMember" xlink:type="locator" xlink:label="us-gaap_StandbyLettersOfCreditMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StandbyLettersOfCreditMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Standby Letters of Credit [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StandbyLettersOfCreditMember" xlink:to="us-gaap_StandbyLettersOfCreditMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StandbyLettersOfCreditMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Standby Letters Of Credit [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BridgeLoanMember" xlink:type="locator" xlink:label="us-gaap_BridgeLoanMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BridgeLoanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Swing Loan [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BridgeLoanMember" xlink:to="us-gaap_BridgeLoanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BridgeLoanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Bridge Loan [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:type="locator" xlink:label="us-gaap_CreditFacilityAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CreditFacilityAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Facility</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CreditFacilityAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Credit Facility [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:type="locator" xlink:label="us-gaap_CreditFacilityDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CreditFacilityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Facility</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_CreditFacilityDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CreditFacilityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Credit Facility [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:type="locator" xlink:label="us-gaap_RevolvingCreditFacilityMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevolvingCreditFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revolving Credit Facility [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevolvingCreditFacilityMember" xlink:to="us-gaap_RevolvingCreditFacilityMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevolvingCreditFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Revolving Credit Facility [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AmendmentTypeAxis" xlink:type="locator" xlink:label="ajg_AmendmentTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="ajg_AmendmentTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amendment Type.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AmendmentTypeAxis" xlink:to="ajg_AmendmentTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_AmendmentTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amendment Type</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmendmentTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Amendment Type [Axis]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AmendmentTypeDomain" xlink:type="locator" xlink:label="ajg_AmendmentTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="ajg_AmendmentTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amendment type.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AmendmentTypeDomain" xlink:to="ajg_AmendmentTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_AmendmentTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amendment Type</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmendmentTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Amendment Type [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BeforeAmendmentMember" xlink:type="locator" xlink:label="ajg_BeforeAmendmentMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_BeforeAmendmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Before amendment.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BeforeAmendmentMember" xlink:to="ajg_BeforeAmendmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_BeforeAmendmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Before Amendment [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BeforeAmendmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Before Amendment [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AfterAmendmentMember" xlink:type="locator" xlink:label="ajg_AfterAmendmentMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_AfterAmendmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">After amendment.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AfterAmendmentMember" xlink:to="ajg_AfterAmendmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_AfterAmendmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">After Amendment [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AfterAmendmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">After Amendment [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CreditFacilityTwoMember" xlink:type="locator" xlink:label="ajg_CreditFacilityTwoMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditFacilityTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Credit Facility Two [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CreditFacilityTwoMember" xlink:to="ajg_CreditFacilityTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditFacilityTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Facility Two [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CreditFacilityTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Credit Facility Two [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CreditFacilityThreeMember" xlink:type="locator" xlink:label="ajg_CreditFacilityThreeMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditFacilityThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Credit Facility Three [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CreditFacilityThreeMember" xlink:to="ajg_CreditFacilityThreeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditFacilityThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Facility Three [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CreditFacilityThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Credit Facility Three [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CreditFacilityFourMember" xlink:type="locator" xlink:label="ajg_CreditFacilityFourMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditFacilityFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Credit Facility Four [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CreditFacilityFourMember" xlink:to="ajg_CreditFacilityFourMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditFacilityFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Facility Four [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CreditFacilityFourMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Credit Facility Four [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Hierarchy and NAV</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value By Fair Value Hierarchy Level [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Hierarchy and NAV</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Measurements Fair Value Hierarchy [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 3 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel3Member" xlink:to="us-gaap_FairValueInputsLevel3Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Inputs Level3 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfFinancialInstitutionsEnteredInUnsecuredMulticurrencyCreditAgreement_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of financial institutions entered in unsecured multicurrency credit agreement</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfFinancialInstitutionsEnteredInUnsecuredMulticurrencyCreditAgreement_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Financial Institutions Entered In Unsecured Multicurrency Credit Agreement</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Line of credit facility, maximum borrowing capacity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Maximum Borrowing Capacity</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentCarryingAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term debt, gross</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_DebtInstrumentCarryingAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Carrying Amount</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Line of credit facility, maximum amount outstanding during period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod" xlink:to="us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Maximum Amount Outstanding During Period</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FixedRateOverLibor" xlink:type="locator" xlink:label="ajg_FixedRateOverLibor" />
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOverLibor_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fixed rate over libor.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FixedRateOverLibor" xlink:to="ajg_FixedRateOverLibor_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AnnualFacilityFeeOfRevolvingCreditFacility" xlink:type="locator" xlink:label="ajg_AnnualFacilityFeeOfRevolvingCreditFacility" />
    <link:label xml:lang="en-US" xlink:label="ajg_AnnualFacilityFeeOfRevolvingCreditFacility_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Annual facility fee of revolving credit facility.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AnnualFacilityFeeOfRevolvingCreditFacility" xlink:to="ajg_AnnualFacilityFeeOfRevolvingCreditFacility_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DebtAcquisitionCosts" xlink:type="locator" xlink:label="ajg_DebtAcquisitionCosts" />
    <link:label xml:lang="en-US" xlink:label="ajg_DebtAcquisitionCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt Acquisition Costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DebtAcquisitionCosts" xlink:to="ajg_DebtAcquisitionCosts_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Interest rates on base rate loans</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOverLibor_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed rate over LIBOR</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FixedRateOverLibor_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fixed Rate Over Libor</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AnnualFacilityFeeOfRevolvingCreditFacility_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Annual facility fee of revolving credit facility</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AnnualFacilityFeeOfRevolvingCreditFacility_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Annual Facility Fee Of Revolving Credit Facility</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DebtAcquisitionCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt acquisition costs</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DebtAcquisitionCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Acquisition Costs</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCredit" xlink:type="locator" xlink:label="us-gaap_LineOfCredit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Line of credit facility, amount outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCredit" xlink:to="us-gaap_LineOfCredit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_Liabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liabilities</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Line of credit facility, fair value of amount outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding" xlink:to="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Fair Value Of Amount Outstanding</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Line of credit facility, remaining borrowing capacity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Remaining Borrowing Capacity</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ProceedsFromDebtFacilityVariableLimits" xlink:type="locator" xlink:label="ajg_ProceedsFromDebtFacilityVariableLimits" />
    <link:label xml:lang="en-US" xlink:label="ajg_ProceedsFromDebtFacilityVariableLimits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds from debt facility variable limits.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ProceedsFromDebtFacilityVariableLimits" xlink:to="ajg_ProceedsFromDebtFacilityVariableLimits_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ProceedsFromDebtFacilityVariableLimits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from debt facility variable limits</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ProceedsFromDebtFacilityVariableLimits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Debt Facility Variable Limits</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromIssuanceOfDebt" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfDebt" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromIssuanceOfDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net borrowings on premium financing debt facility</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfDebt" xlink:to="us-gaap_ProceedsFromIssuanceOfDebt_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromIssuanceOfDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Issuance Of Debt</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InterestRateTermDebtTransactions" xlink:type="locator" xlink:label="ajg_InterestRateTermDebtTransactions" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterestRateTermDebtTransactions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest Rate Term Debt Transactions</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InterestRateTermDebtTransactions" xlink:to="ajg_InterestRateTermDebtTransactions_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterestRateTermDebtTransactions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional margin percentage on interest rate</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InterestRateTermDebtTransactions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Rate Term Debt Transactions</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Annual fee percentage</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:to="us-gaap_LineOfCreditFacilityCommitmentFeePercentage_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Commitment Fee Percentage</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateDescription" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDescription" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDescription_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest rate for facility</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInterestRateDescription" xlink:to="us-gaap_LineOfCreditFacilityInterestRateDescription_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDescription_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Interest Rate Description</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebt" xlink:type="locator" xlink:label="us-gaap_LongTermDebt" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term debt</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebt" xlink:to="us-gaap_LongTermDebt_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LinesOfCreditFairValueDisclosure" xlink:type="locator" xlink:label="us-gaap_LinesOfCreditFairValueDisclosure" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LinesOfCreditFairValueDisclosure_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated fair value of outstanding borrowings</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LinesOfCreditFairValueDisclosure" xlink:to="us-gaap_LinesOfCreditFairValueDisclosure_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LinesOfCreditFairValueDisclosure_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lines Of Credit Fair Value Disclosure</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentFairValue" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentFairValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument fair value amount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFairValue" xlink:to="us-gaap_DebtInstrumentFairValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Fair Value</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_WeightedAverageNumberOfCommonAndCommonEquivalentSharesOutstanding" xlink:type="locator" xlink:label="ajg_WeightedAverageNumberOfCommonAndCommonEquivalentSharesOutstanding" />
    <link:label xml:lang="en-US" xlink:label="ajg_WeightedAverageNumberOfCommonAndCommonEquivalentSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Weighted Average Number Of Common And Common Equivalent Shares Outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_WeightedAverageNumberOfCommonAndCommonEquivalentSharesOutstanding" xlink:to="ajg_WeightedAverageNumberOfCommonAndCommonEquivalentSharesOutstanding_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net earnings attributable to controlling interests</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average number of common shares outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number Of Shares Outstanding Basic</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:type="locator" xlink:label="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Dilutive effect of stock options using the treasury stock method</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:to="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Incremental Common Shares Attributable To Share Based Payment Arrangements</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_WeightedAverageNumberOfCommonAndCommonEquivalentSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Weighted average number of common and common equivalent shares outstanding</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_WeightedAverageNumberOfCommonAndCommonEquivalentSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number Of Common And Common Equivalent Shares Outstanding</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:type="locator" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Anti-dilutive stock-based awards shares outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_StockOptionPlansLineItems" xlink:type="locator" xlink:label="ajg_StockOptionPlansLineItems" />
    <link:label xml:lang="en-US" xlink:label="ajg_StockOptionPlansLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Stock Option Plans [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_StockOptionPlansLineItems" xlink:to="ajg_StockOptionPlansLineItems_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AnnualActivityOfStockOptionPlansTable" xlink:type="locator" xlink:label="ajg_AnnualActivityOfStockOptionPlansTable" />
    <link:label xml:lang="en-US" xlink:label="ajg_AnnualActivityOfStockOptionPlansTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Annual Activity Of Stock Option Plans [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AnnualActivityOfStockOptionPlansTable" xlink:to="ajg_AnnualActivityOfStockOptionPlansTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_AnnualActivityOfStockOptionPlansTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Annual Activity Of Stock Option Plans [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AnnualActivityOfStockOptionPlansTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Annual Activity Of Stock Option Plans [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameAxis" xlink:type="locator" xlink:label="us-gaap_PlanNameAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PlanNameAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Plan Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PlanNameAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Plan Name [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameDomain" xlink:type="locator" xlink:label="us-gaap_PlanNameDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PlanNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Plan Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameDomain" xlink:to="us-gaap_PlanNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PlanNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Plan Name [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_LongTermIncentivePlanMember" xlink:type="locator" xlink:label="ajg_LongTermIncentivePlanMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_LongTermIncentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Long Term Incentive Plan [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_LongTermIncentivePlanMember" xlink:to="ajg_LongTermIncentivePlanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_LongTermIncentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long Term Incentive Plan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_LongTermIncentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Incentive Plan [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandSeventeenLongTermincentivePlanMember" xlink:type="locator" xlink:label="ajg_TwoThousandSeventeenLongTermincentivePlanMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandSeventeenLongTermincentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">2017 Long Term Incentive Plan [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandSeventeenLongTermincentivePlanMember" xlink:to="ajg_TwoThousandSeventeenLongTermincentivePlanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandSeventeenLongTermincentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2017 Long Term Incentive Plan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandSeventeenLongTermincentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Seventeen Long Termincentive Plan [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualAxis" xlink:type="locator" xlink:label="srt_TitleOfIndividualAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_TitleOfIndividualAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Title of Individual</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_TitleOfIndividualAxis" xlink:to="srt_TitleOfIndividualAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_TitleOfIndividualAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Title Of Individual [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:type="locator" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Title of Individual</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:to="srt_TitleOfIndividualWithRelationshipToEntityDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Title Of Individual With Relationship To Entity [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_OfficerMember" xlink:type="locator" xlink:label="srt_OfficerMember" />
    <link:label xml:lang="en-US" xlink:label="srt_OfficerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Officer and Key Employees [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_OfficerMember" xlink:to="srt_OfficerMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_OfficerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Officer [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ExecutiveOfficerMember" xlink:type="locator" xlink:label="srt_ExecutiveOfficerMember" />
    <link:label xml:lang="en-US" xlink:label="srt_ExecutiveOfficerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Executive Officer [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ExecutiveOfficerMember" xlink:to="srt_ExecutiveOfficerMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ExecutiveOfficerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Executive Officer [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_BlackScholesOptionPricingModelMember" xlink:type="locator" xlink:label="ajg_BlackScholesOptionPricingModelMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_BlackScholesOptionPricingModelMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Black-Scholes Option Pricing Model [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_BlackScholesOptionPricingModelMember" xlink:to="ajg_BlackScholesOptionPricingModelMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_BlackScholesOptionPricingModelMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Black-Scholes Option Pricing Model [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_BlackScholesOptionPricingModelMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Black Scholes Option Pricing Model [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_StockOptionPlansLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock Option Plans [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_StockOptionPlansLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Option Plans [Line Items]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum number of shares available</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfPeriodsOptionsExpire" xlink:type="locator" xlink:label="ajg_NumberOfPeriodsOptionsExpire" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfPeriodsOptionsExpire_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of years options expire.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfPeriodsOptionsExpire" xlink:to="ajg_NumberOfPeriodsOptionsExpire_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ExercisePriceOfStockOptionsPercentOfFairMarketValueOfShareOfCommonStockOnDateOfGrant" xlink:type="locator" xlink:label="ajg_ExercisePriceOfStockOptionsPercentOfFairMarketValueOfShareOfCommonStockOnDateOfGrant" />
    <link:label xml:lang="en-US" xlink:label="ajg_ExercisePriceOfStockOptionsPercentOfFairMarketValueOfShareOfCommonStockOnDateOfGrant_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Exercise Price Of Stock Options Percent Of Fair Market Value Of Share Of Common Stock On Date Of Grant.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ExercisePriceOfStockOptionsPercentOfFairMarketValueOfShareOfCommonStockOnDateOfGrant" xlink:to="ajg_ExercisePriceOfStockOptionsPercentOfFairMarketValueOfShareOfCommonStockOnDateOfGrant_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfPeriodsOptionsExpire_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number Of Periods Options Expire</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfPeriodsOptionsExpire_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Periods Options Expire</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ExercisePriceOfStockOptionsPercentOfFairMarketValueOfShareOfCommonStockOnDateOfGrant_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum exercise price of stock options, percent of fair market value of a share of common stock on the date of grant</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ExercisePriceOfStockOptionsPercentOfFairMarketValueOfShareOfCommonStockOnDateOfGrant_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Exercise Price Of Stock Options Percent Of Fair Market Value Of Share Of Common Stock On Date Of Grant</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearOne" xlink:type="locator" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearOne" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangement by share based payment award options grants in period exercise percentage year one.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearOne" xlink:to="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearOne_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearTwo" xlink:type="locator" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearTwo" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangement by share based payment award options grants in period exercise percentage year two.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearTwo" xlink:to="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearTwo_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearThree" xlink:type="locator" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearThree" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangement by share based payment award options grants in period exercise percentage year three.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearThree" xlink:to="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearThree_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PeriodForOptionsToExpireFromDateOfGrant" xlink:type="locator" xlink:label="ajg_PeriodForOptionsToExpireFromDateOfGrant" />
    <link:label xml:lang="en-US" xlink:label="ajg_PeriodForOptionsToExpireFromDateOfGrant_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Period for options to expire from date of grant.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PeriodForOptionsToExpireFromDateOfGrant" xlink:to="ajg_PeriodForOptionsToExpireFromDateOfGrant_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AgeOfEmployeeNoLongerSubjectToAwardForfeitureOnConditionCompliance" xlink:type="locator" xlink:label="ajg_AgeOfEmployeeNoLongerSubjectToAwardForfeitureOnConditionCompliance" />
    <link:label xml:lang="en-US" xlink:label="ajg_AgeOfEmployeeNoLongerSubjectToAwardForfeitureOnConditionCompliance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Age Of Employee No Longer Subject To Award Forfeiture On Condition Compliance</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AgeOfEmployeeNoLongerSubjectToAwardForfeitureOnConditionCompliance" xlink:to="ajg_AgeOfEmployeeNoLongerSubjectToAwardForfeitureOnConditionCompliance_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PeriodOfServiceFromGrantDateStockOptionsAwardedNotSubjectToForfeiture" xlink:type="locator" xlink:label="ajg_PeriodOfServiceFromGrantDateStockOptionsAwardedNotSubjectToForfeiture" />
    <link:label xml:lang="en-US" xlink:label="ajg_PeriodOfServiceFromGrantDateStockOptionsAwardedNotSubjectToForfeiture_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Period Of Service From Grant Date Stock Options Awarded Not Subject To Forfeiture</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PeriodOfServiceFromGrantDateStockOptionsAwardedNotSubjectToForfeiture" xlink:to="ajg_PeriodOfServiceFromGrantDateStockOptionsAwardedNotSubjectToForfeiture_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock options granted, exercise percentage, on the third anniversary date of the grant</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Exercise Percentage Year One</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock options granted, exercise percentage, on the fourth anniversary date of the grant</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Exercise Percentage Year Two</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock options granted, exercise percentage, on the fifth anniversary date of the grant</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodExercisePercentageYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Exercise Percentage Year Three</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PeriodForOptionsToExpireFromDateOfGrant_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum period for the exercise of stock options, years</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PeriodForOptionsToExpireFromDateOfGrant_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Period For Options To Expire From Date Of Grant</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AgeOfEmployeeNoLongerSubjectToAwardForfeitureOnConditionCompliance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum age of employee with not subject to award forfeiture on condition compliance</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AgeOfEmployeeNoLongerSubjectToAwardForfeitureOnConditionCompliance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Age Of Employee No Longer Subject To Award Forfeiture On Condition Compliance</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PeriodOfServiceFromGrantDateStockOptionsAwardedNotSubjectToForfeiture_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Period of service from grant date stock options awarded not subject to forfeiture</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PeriodOfServiceFromGrantDateStockOptionsAwardedNotSubjectToForfeiture_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Period Of Service From Grant Date Stock Options Awarded Not Subject To Forfeiture</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockGrantedDuringPeriodValueSharebasedCompensation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Compensation expense related to stock option grants</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPerShare" xlink:type="locator" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPerShare" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPerShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangement by share based payment award, fair value assumptions, expected dividend per share.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPerShare" xlink:to="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPerShare_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPerShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected dividend yield</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPerShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Per Share</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected risk-free interest rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Volatility</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected life (in years)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average fair value per option for all options</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonVestedAndExpectedToVestNumberOfShares" xlink:type="locator" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonVestedAndExpectedToVestNumberOfShares" />
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    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisedInPeriodIntrinsicValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share-based compensation arrangement by share based payment award options exercised in period intrinsic value.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisedInPeriodIntrinsicValue" xlink:to="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisedInPeriodIntrinsicValue_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_WeightedAveragePeriod" xlink:type="locator" xlink:label="ajg_WeightedAveragePeriod" />
    <link:label xml:lang="en-US" xlink:label="ajg_WeightedAveragePeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Weighted Average Period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_WeightedAveragePeriod" xlink:to="ajg_WeightedAveragePeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisedInPeriodIntrinsicValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total intrinsic value of options exercised</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisedInPeriodIntrinsicValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Exercised In Period Intrinsic Value</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:type="locator" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total unrecognized compensation cost related to nonvested options</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_WeightedAveragePeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average period, years</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_WeightedAveragePeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Period</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Share Based Compensation Shares Authorized Under Stock Option Plans By Exercise Price Range [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:to="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Share Based Compensation Shares Authorized Under Stock Option Plans By Exercise Price Range [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise Price Range</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Shares Authorized Under Stock Option Plans By Exercise Price Range [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise Price Range</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_Range01Member" xlink:type="locator" xlink:label="ajg_Range01Member" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range01Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Range 01 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_Range01Member" xlink:to="ajg_Range01Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range01Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise Prices Range $ 43.71 - $ 43.71 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_Range01Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Range01 [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_Range02Member" xlink:type="locator" xlink:label="ajg_Range02Member" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range02Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Range 02 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_Range02Member" xlink:to="ajg_Range02Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range02Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise Prices Range $ 46.17 - $ 46.87 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_Range02Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Range02 [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_Range03Member" xlink:type="locator" xlink:label="ajg_Range03Member" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range03Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Range 03 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_Range03Member" xlink:to="ajg_Range03Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range03Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise Prices Range $ 49.55 - $ 56.86 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_Range03Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Range03 [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_Range04Member" xlink:type="locator" xlink:label="ajg_Range04Member" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range04Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Range 04 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_Range04Member" xlink:to="ajg_Range04Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range04Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise Prices Range $ 70.74 - $ 70.74 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_Range04Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Range04 [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_Range05Member" xlink:type="locator" xlink:label="ajg_Range05Member" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range05Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Range 05 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_Range05Member" xlink:to="ajg_Range05Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range05Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise Prices Range $ 79.59 - $ 79.59 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_Range05Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Range05 [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_Range06Member" xlink:type="locator" xlink:label="ajg_Range06Member" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range06Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Range 06 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_Range06Member" xlink:to="ajg_Range06Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_Range06Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise Prices Range $ 86.17 - $ 86.17 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_Range06Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Range06 [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Range of Exercise Prices, minimum</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Lower Range Limit</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Range of Exercise Prices, maximum</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Upper Range Limit</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Option Outstanding, Number Outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Number Of Outstanding Options</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Option Outstanding, Weighted Average Remaining Contractual Term (in years)</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Option Outstanding, Weighted Average Exercise Price</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Options Exercisable, Number Exercisable</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Number Of Exercisable Options</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Option Exercisable, Weighted Average Exercise Price</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" xlink:to="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Exercisable Options Weighted Average Exercise Price1</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredEquityParticipationPlanDistributionsToKeyExecutivesAge" xlink:type="locator" xlink:label="ajg_DeferredEquityParticipationPlanDistributionsToKeyExecutivesAge" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationPlanDistributionsToKeyExecutivesAge_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Equity Participation Plan, Distributions to Key Executives, Age</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DeferredEquityParticipationPlanDistributionsToKeyExecutivesAge" xlink:to="ajg_DeferredEquityParticipationPlanDistributionsToKeyExecutivesAge_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredEquityParticipationSubPlanDistributionsRequisiteServiceDescription" xlink:type="locator" xlink:label="ajg_DeferredEquityParticipationSubPlanDistributionsRequisiteServiceDescription" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationSubPlanDistributionsRequisiteServiceDescription_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred equity participation sub plan distributions requisite service description.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DeferredEquityParticipationSubPlanDistributionsRequisiteServiceDescription" xlink:to="ajg_DeferredEquityParticipationSubPlanDistributionsRequisiteServiceDescription_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredEquityParticipationSubPlanDistributionsToKeyExecutivesAge" xlink:type="locator" xlink:label="ajg_DeferredEquityParticipationSubPlanDistributionsToKeyExecutivesAge" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationSubPlanDistributionsToKeyExecutivesAge_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred equity participation sub plan distributions to key executives age.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DeferredEquityParticipationSubPlanDistributionsToKeyExecutivesAge" xlink:to="ajg_DeferredEquityParticipationSubPlanDistributionsToKeyExecutivesAge_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ScheduleOfSaleOfSubsidiaryAbstract" xlink:type="locator" xlink:label="ajg_ScheduleOfSaleOfSubsidiaryAbstract" />
    <link:label xml:lang="en-US" xlink:label="ajg_ScheduleOfSaleOfSubsidiaryAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule Of Sale Of Subsidiary [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ScheduleOfSaleOfSubsidiaryAbstract" xlink:to="ajg_ScheduleOfSaleOfSubsidiaryAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ScheduleOfSaleOfSubsidiaryAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Sale Of Subsidiary [Abstract]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InvestmentsAndEmployeeDeferredCompensationPlanLineItems" xlink:type="locator" xlink:label="ajg_InvestmentsAndEmployeeDeferredCompensationPlanLineItems" />
    <link:label xml:lang="en-US" xlink:label="ajg_InvestmentsAndEmployeeDeferredCompensationPlanLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Investments And Employee Deferred Compensation Plan [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InvestmentsAndEmployeeDeferredCompensationPlanLineItems" xlink:to="ajg_InvestmentsAndEmployeeDeferredCompensationPlanLineItems_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InvestmentsAndEmployeeDeferredCompensationPlanTable" xlink:type="locator" xlink:label="ajg_InvestmentsAndEmployeeDeferredCompensationPlanTable" />
    <link:label xml:lang="en-US" xlink:label="ajg_InvestmentsAndEmployeeDeferredCompensationPlanTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Investments And Employee Deferred Compensation Plan [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InvestmentsAndEmployeeDeferredCompensationPlanTable" xlink:to="ajg_InvestmentsAndEmployeeDeferredCompensationPlanTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_InvestmentsAndEmployeeDeferredCompensationPlanTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investments And Employee Deferred Compensation Plan [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InvestmentsAndEmployeeDeferredCompensationPlanTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investments And Employee Deferred Compensation Plan [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:type="locator" xlink:label="us-gaap_AwardTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AwardTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Award Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_AwardTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AwardTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Award Type [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Award Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredEquityParticipationPlanMember" xlink:type="locator" xlink:label="ajg_DeferredEquityParticipationPlanMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred equity participation plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DeferredEquityParticipationPlanMember" xlink:to="ajg_DeferredEquityParticipationPlanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Equity Participation Plan (DEPP) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Equity Participation Plan [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredEquityParticipationPlanSubPlansMember" xlink:type="locator" xlink:label="ajg_DeferredEquityParticipationPlanSubPlansMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationPlanSubPlansMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred equity participation plan sub plans.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DeferredEquityParticipationPlanSubPlansMember" xlink:to="ajg_DeferredEquityParticipationPlanSubPlansMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationPlanSubPlansMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Equity Participation Plan Sub Plans [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationPlanSubPlansMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Equity Participation Plan Sub Plans [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredCashParticipationPlanMember" xlink:type="locator" xlink:label="ajg_DeferredCashParticipationPlanMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredCashParticipationPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Cash Participation Plan [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DeferredCashParticipationPlanMember" xlink:to="ajg_DeferredCashParticipationPlanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredCashParticipationPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Cash Participation Plan (DCPP) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredCashParticipationPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Cash Participation Plan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InvestmentsAndEmployeeDeferredCompensationPlanLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investments And Employee Deferred Compensation Plan [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InvestmentsAndEmployeeDeferredCompensationPlanLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investments And Employee Deferred Compensation Plan [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationPlanDistributionsToKeyExecutivesAge_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Equity Participation Plan, distributions to key executives, age</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationPlanDistributionsToKeyExecutivesAge_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Equity Participation Plan Distributions To Key Executives Age</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationSubPlanDistributionsRequisiteServiceDescription_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Equity Participation Sub-plans, distributions requisite service description</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationSubPlanDistributionsRequisiteServiceDescription_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Equity Participation Sub Plan Distributions Requisite Service Description</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationSubPlanDistributionsToKeyExecutivesAge_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Equity Participation Sub-plans, distributions to key executives, age</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredEquityParticipationSubPlanDistributionsToKeyExecutivesAge_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Equity Participation Sub Plan Distributions To Key Executives Age</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CompensationApprovedByCommitteeValue" xlink:type="locator" xlink:label="ajg_CompensationApprovedByCommitteeValue" />
    <link:label xml:lang="en-US" xlink:label="ajg_CompensationApprovedByCommitteeValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Compensation approved by committee, value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CompensationApprovedByCommitteeValue" xlink:to="ajg_CompensationApprovedByCommitteeValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CompensationApprovedByCommitteeValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Awards approved by committee, value</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CompensationApprovedByCommitteeValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Compensation Approved By Committee Value</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:type="locator" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Charge to compensation expenses related to awards</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllocatedShareBasedCompensationExpense" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Allocated Share Based Compensation Expense</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ProceedsFromSubPlan" xlink:type="locator" xlink:label="ajg_ProceedsFromSubPlan" />
    <link:label xml:lang="en-US" xlink:label="ajg_ProceedsFromSubPlan_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds From Sub Plan</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ProceedsFromSubPlan" xlink:to="ajg_ProceedsFromSubPlan_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ProceedsFromSubPlan_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Distributions from the sub-plans</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ProceedsFromSubPlan_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Sub Plan</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UnearnedDeferredCompensationValue" xlink:type="locator" xlink:label="ajg_UnearnedDeferredCompensationValue" />
    <link:label xml:lang="en-US" xlink:label="ajg_UnearnedDeferredCompensationValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Unearned Deferred Compensation, Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UnearnedDeferredCompensationValue" xlink:to="ajg_UnearnedDeferredCompensationValue_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UnearnedDeferredCompensationShare" xlink:type="locator" xlink:label="ajg_UnearnedDeferredCompensationShare" />
    <link:label xml:lang="en-US" xlink:label="ajg_UnearnedDeferredCompensationShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Unearned Deferred Compensation, Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UnearnedDeferredCompensationShare" xlink:to="ajg_UnearnedDeferredCompensationShare_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CashAndEquityAwardWithAggregateFairValueVestedAndDistributedToParticipants" xlink:type="locator" xlink:label="ajg_CashAndEquityAwardWithAggregateFairValueVestedAndDistributedToParticipants" />
    <link:label xml:lang="en-US" xlink:label="ajg_CashAndEquityAwardWithAggregateFairValueVestedAndDistributedToParticipants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash and equity award with aggregate fair value vested and distributed to participants.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CashAndEquityAwardWithAggregateFairValueVestedAndDistributedToParticipants" xlink:to="ajg_CashAndEquityAwardWithAggregateFairValueVestedAndDistributedToParticipants_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_UnearnedDeferredCompensationValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unearned deferred compensation, value</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UnearnedDeferredCompensationValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unearned Deferred Compensation Value</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UnearnedDeferredCompensationShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unearned deferred compensation, shares</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UnearnedDeferredCompensationShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unearned Deferred Compensation Share</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total intrinsic value of unvested equity based awards</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CashAndEquityAwardWithAggregateFairValueVestedAndDistributedToParticipants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash and equity awards with aggregate fair value vested and distributed to participants</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CashAndEquityAwardWithAggregateFairValueVestedAndDistributedToParticipants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash And Equity Award With Aggregate Fair Value Vested And Distributed To Participants</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingValue" xlink:type="locator" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingValue" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingValue" xlink:to="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingValue_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationLineItems" xlink:type="locator" xlink:label="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationLineItems" />
    <link:label xml:lang="en-US" xlink:label="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationLineItems" xlink:to="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationLineItems_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationTable" xlink:type="locator" xlink:label="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationTable" />
    <link:label xml:lang="en-US" xlink:label="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationTable" xlink:to="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:type="locator" xlink:label="us-gaap_RestrictedStockUnitsRSUMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedStockUnitsRSUMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted Stock Units (RSUs) [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockUnitsRSUMember" xlink:to="us-gaap_RestrictedStockUnitsRSUMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedStockUnitsRSUMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Stock Units R S U [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UnvestedRestrictedStockMember" xlink:type="locator" xlink:label="ajg_UnvestedRestrictedStockMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_UnvestedRestrictedStockMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Unvested Restricted Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UnvestedRestrictedStockMember" xlink:to="ajg_UnvestedRestrictedStockMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_UnvestedRestrictedStockMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unvested Restricted Stock [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UnvestedRestrictedStockMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unvested Restricted Stock [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PerformanceSharesMember" xlink:type="locator" xlink:label="us-gaap_PerformanceSharesMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PerformanceSharesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Performance Shares [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PerformanceSharesMember" xlink:to="us-gaap_PerformanceSharesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PerformanceSharesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Performance Shares [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandSeventeenPerformanceShareAwardsMember" xlink:type="locator" xlink:label="ajg_TwoThousandSeventeenPerformanceShareAwardsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandSeventeenPerformanceShareAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Seventeen Performance Share Awards [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandSeventeenPerformanceShareAwardsMember" xlink:to="ajg_TwoThousandSeventeenPerformanceShareAwardsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandSeventeenPerformanceShareAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2017 Performance Share Awards [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandSeventeenPerformanceShareAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Seventeen Performance Share Awards [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CashAwardsMember" xlink:type="locator" xlink:label="ajg_CashAwardsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash Awards [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CashAwardsMember" xlink:to="ajg_CashAwardsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash Awards [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash Awards [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandTwentyProvisionalCashAwardsMember" xlink:type="locator" xlink:label="ajg_TwoThousandTwentyProvisionalCashAwardsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandTwentyProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two thousand twenty provisional cash awards.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandTwentyProvisionalCashAwardsMember" xlink:to="ajg_TwoThousandTwentyProvisionalCashAwardsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandTwentyProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2020 Provisional Cash Awards [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandTwentyProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Twenty Provisional Cash Awards [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandNineteenProvisionalCashAwardsMember" xlink:type="locator" xlink:label="ajg_TwoThousandNineteenProvisionalCashAwardsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandNineteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Nineteen Provisional Cash Awards [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandNineteenProvisionalCashAwardsMember" xlink:to="ajg_TwoThousandNineteenProvisionalCashAwardsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandNineteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2019 Provisional Cash Awards [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandNineteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Nineteen Provisional Cash Awards [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandEighteenProvisionalCashAwardsMember" xlink:type="locator" xlink:label="ajg_TwoThousandEighteenProvisionalCashAwardsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandEighteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Eighteen Provisional Cash Awards [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandEighteenProvisionalCashAwardsMember" xlink:to="ajg_TwoThousandEighteenProvisionalCashAwardsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandEighteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2018 Provisional Cash Awards [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandEighteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Eighteen Provisional Cash Awards [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandSixteenProvisionalCashAwardsMember" xlink:type="locator" xlink:label="ajg_TwoThousandSixteenProvisionalCashAwardsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandSixteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Sixteen Provisional Cash Awards [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandSixteenProvisionalCashAwardsMember" xlink:to="ajg_TwoThousandSixteenProvisionalCashAwardsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandSixteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2016 Provisional Cash Awards [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandSixteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Sixteen Provisional Cash Awards [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandFifteenProvisionalCashAwardsMember" xlink:type="locator" xlink:label="ajg_TwoThousandFifteenProvisionalCashAwardsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandFifteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Fifteen Provisional Cash Awards [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandFifteenProvisionalCashAwardsMember" xlink:to="ajg_TwoThousandFifteenProvisionalCashAwardsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandFifteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2015 Provisional Cash Awards [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandFifteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Fifteen Provisional Cash Awards [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandFourteenProvisionalCashAwardsMember" xlink:type="locator" xlink:label="ajg_TwoThousandFourteenProvisionalCashAwardsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandFourteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Fourteen Provisional Cash Awards [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandFourteenProvisionalCashAwardsMember" xlink:to="ajg_TwoThousandFourteenProvisionalCashAwardsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandFourteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2014 Provisional Cash Awards [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandFourteenProvisionalCashAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Fourteen Provisional Cash Awards [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CommonStockOptionsRestrictedStockWarrantsAndChangesInCapitalizationLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share-based compensation, shares outstanding, Value</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Value</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share-based compensation, shares outstanding</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Shares granted in the period</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodFairValue" xlink:type="locator" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodFairValue" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Fair Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodFairValue" xlink:to="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodFairValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair value of grants in period</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Fair Value</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingDate" xlink:type="locator" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingDate" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Date</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingDate" xlink:to="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingDate_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share based payment award vesting date</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Date</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_VestingPeriodLineItems" xlink:type="locator" xlink:label="ajg_VestingPeriodLineItems" />
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Vesting Period [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_VestingPeriodLineItems" xlink:to="ajg_VestingPeriodLineItems_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_VestingPeriodTable" xlink:type="locator" xlink:label="ajg_VestingPeriodTable" />
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Vesting Period [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_VestingPeriodTable" xlink:to="ajg_VestingPeriodTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting Period [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Vesting Period [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedStockUnitsRSUMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Restricted Stock Units Granted [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_VestingPeriodOneYearMember" xlink:type="locator" xlink:label="ajg_VestingPeriodOneYearMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodOneYearMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Vesting Period One Year [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_VestingPeriodOneYearMember" xlink:to="ajg_VestingPeriodOneYearMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodOneYearMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting Period One Year [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodOneYearMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Vesting Period One Year [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_VestingPeriodTwoYearsMember" xlink:type="locator" xlink:label="ajg_VestingPeriodTwoYearsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodTwoYearsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Vesting Period Two Years [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_VestingPeriodTwoYearsMember" xlink:to="ajg_VestingPeriodTwoYearsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodTwoYearsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting Period Two Years [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodTwoYearsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Vesting Period Two Years [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_VestingPeriodFiveYearsMember" xlink:type="locator" xlink:label="ajg_VestingPeriodFiveYearsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodFiveYearsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Vesting Period Five Years [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_VestingPeriodFiveYearsMember" xlink:to="ajg_VestingPeriodFiveYearsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodFiveYearsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting Period Five Years [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodFiveYearsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Vesting Period Five Years [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting Period [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_VestingPeriodLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Vesting Period [Line Items]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting period, years</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionNonvestedIntrinsicValue" xlink:type="locator" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionNonvestedIntrinsicValue" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionNonvestedIntrinsicValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Option Nonvested Intrinsic Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionNonvestedIntrinsicValue" xlink:to="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionNonvestedIntrinsicValue_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockExpense" xlink:type="locator" xlink:label="us-gaap_RestrictedStockExpense" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedStockExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted stock or unit expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockExpense" xlink:to="us-gaap_RestrictedStockExpense_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedStockExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Stock Expense</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionNonvestedIntrinsicValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total intrinsic value</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionNonvestedIntrinsicValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Option Nonvested Intrinsic Value</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity awards with an aggregate fair value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairValue" xlink:type="locator" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairValue" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement By Share Based Payment Award Aggregate Fair Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairValue" xlink:to="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Performance share awards approved, Fair value</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Aggregate Fair Value</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Provisional awards, terms</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Terms Of Award</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeValue" xlink:type="locator" xlink:label="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeValue" />
    <link:label xml:lang="en-US" xlink:label="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Provisional Compensation Cash Award Approved for Future Grant by Compensation Committee, Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeValue" xlink:to="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeValue_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeUnits" xlink:type="locator" xlink:label="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeUnits" />
    <link:label xml:lang="en-US" xlink:label="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeUnits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Provisional compensation cash award approved for future grant by compensation committee, units</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeUnits" xlink:to="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeUnits_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMinimum" xlink:type="locator" xlink:label="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMinimum" />
    <link:label xml:lang="en-US" xlink:label="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMinimum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Ultimate Award Value Multiples of Original Value of Units, Minimum</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMinimum" xlink:to="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMinimum_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMaximum" xlink:type="locator" xlink:label="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMaximum" />
    <link:label xml:lang="en-US" xlink:label="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMaximum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Ultimate Award Value Multiples of Original Value of Units, Maximum</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMaximum" xlink:to="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMaximum_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CashBasedCompensationAwardExpenses" xlink:type="locator" xlink:label="ajg_CashBasedCompensationAwardExpenses" />
    <link:label xml:lang="en-US" xlink:label="ajg_CashBasedCompensationAwardExpenses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash based compensation award, expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CashBasedCompensationAwardExpenses" xlink:to="ajg_CashBasedCompensationAwardExpenses_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Provisional compensation cash awards approved for future grant by compensation committee, value</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Provisional Compensation Cash Award Approved For Future Grant By Compensation Committee Value</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeUnits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Provisional compensation cash award approved for future grant by compensation committee, units</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ProvisionalCompensationCashAwardApprovedForFutureGrantByCompensationCommitteeUnits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Provisional Compensation Cash Award Approved For Future Grant By Compensation Committee Units</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Performance awards period, years</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sharebased Compensation Arrangement By Sharebased Payment Award Expiration Period</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMinimum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Ultimate award value, multiples of original value of the units, minimum</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMinimum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Ultimate Award Value Multiples Of Original Value Of Units Minimum</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMaximum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Ultimate award value, multiples of original value of the units, maximum</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UltimateAwardValueMultiplesOfOriginalValueOfUnitsMaximum_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Ultimate Award Value Multiples Of Original Value Of Units Maximum</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CashBasedCompensationAwardExpenses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash-based compensation awards, expenses</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CashBasedCompensationAwardExpenses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash Based Compensation Award Expenses</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Performance awards expiration date</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Expiration Date</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DefinedBenefitPlanNetAmountIncludedInRetainedEarning" xlink:type="locator" xlink:label="ajg_DefinedBenefitPlanNetAmountIncludedInRetainedEarning" />
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlanNetAmountIncludedInRetainedEarning_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined benefit plan net amount included in retained earning.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DefinedBenefitPlanNetAmountIncludedInRetainedEarning" xlink:to="ajg_DefinedBenefitPlanNetAmountIncludedInRetainedEarning_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in pension benefit obligation:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" xlink:to="us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Change In Benefit Obligation Roll Forward</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligation" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Benefit obligation at beginning of year</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanBenefitObligation" xlink:to="us-gaap_DefinedBenefitPlanBenefitObligation_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Benefit Obligation</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanServiceCost" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanServiceCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Service cost</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanServiceCost" xlink:to="us-gaap_DefinedBenefitPlanServiceCost_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanServiceCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Service Cost</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanInterestCost" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanInterestCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest cost</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanInterestCost" xlink:to="us-gaap_DefinedBenefitPlanInterestCost_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanInterestCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Interest Cost</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanActuarialGainLoss" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanActuarialGainLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Net actuarial loss</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:to="us-gaap_DefinedBenefitPlanActuarialGainLoss_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanActuarialGainLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Actuarial Gain Loss</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Benefits paid</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:to="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Benefit Obligation Benefits Paid</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Benefit obligation at end of year</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in plan assets:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward" xlink:to="us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Fair value of plan assets at beginning of year</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Fair Value Of Plan Assets</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Actual return on plan assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Actual Return On Plan Assets</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount" xlink:type="locator" xlink:label="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contributions by the company</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount" xlink:to="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Contribution Plan Employer Discretionary Contribution Amount</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Benefits paid</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:to="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Plan Assets Benefits Paid</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Fair value of plan assets at end of year</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanFundedStatusOfPlan" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanFundedStatusOfPlan_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Funded status of the plan (underfunded)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:to="us-gaap_DefinedBenefitPlanFundedStatusOfPlan_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanFundedStatusOfPlan_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Funded Status Of Plan</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amounts recognized in the consolidated balance sheet consist of:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" xlink:to="us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Amounts Recognized In Balance Sheet [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Noncurrent liabilities - accrued benefit liability</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:to="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Accumulated other comprehensive loss - net actuarial loss</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax" xlink:to="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Accumulated Other Comprehensive Income Net Gains Losses Before Tax</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlanNetAmountIncludedInRetainedEarning_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net amount included in retained earnings</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlanNetAmountIncludedInRetainedEarning_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Net Amount Included In Retained Earning</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net periodic pension cost:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract" xlink:to="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Net Periodic Benefit Cost [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanInterestCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Interest cost on benefit obligation</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Expected return on plan assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Expected Return On Plan Assets</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Amortization of net loss</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:to="us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Amortization Of Gains Losses</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net periodic benefit cost</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:to="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Net Periodic Benefit Cost</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other changes in plan assets and obligations recognized in other comprehensive earnings:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract" xlink:to="us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Amounts Recognized In Other Comprehensive Income [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax" xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Net loss incurred</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax" xlink:to="us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax" xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Amortization of net loss</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax" xlink:to="us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income Loss Amortization Adjustment From A O C I Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Before Tax</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax" xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total recognized in other comprehensive loss</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax" xlink:to="us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax" xlink:type="locator" xlink:label="us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total recognized in net periodic pension cost and other comprehensive loss</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax" xlink:to="us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Amount Recognized In Net Periodic Benefit Cost And Other Comprehensive Income Loss Before Tax</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated amortization for the following year:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract" xlink:to="us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Amounts That Will Be Amortized From Accumulated Other Comprehensive Income Loss In Next Fiscal Year [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of net loss</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear" xlink:to="us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Expected Amortization Next Fiscal Year</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnPlanAssets" xlink:type="locator" xlink:label="ajg_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnPlanAssets" />
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined benefit plan, assumptions used calculating benefit obligation, expected long-term return on plan assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnPlanAssets" xlink:to="ajg_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnPlanAssets_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Weighted Average Assumptions Used In Calculating Benefit Obligation [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract" xlink:to="us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Discount rate, pension benefit obligation</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:to="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_lbl" />
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    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average expected long-term rate of return on plan assets, pension benefit obligation</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average expected long-term rate of return on plan assets, net periodic pension benefit cost</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2021</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2022</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Expected Future Benefit Payments Year Two</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Expected Future Benefit Payments Year Three</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Expected Future Benefit Payments Year Four</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Expected Future Benefit Payments Year Five</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Years 2026 to 2030</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanDebtSecurityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Debt Security [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanDisclosureLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Disclosure [Line Items]</link:label>
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_ExpectedPeriodOfReturnOnPlanAssets" xlink:type="locator" xlink:label="ajg_ExpectedPeriodOfReturnOnPlanAssets" />
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    <link:label xml:lang="en-US" xlink:label="ajg_NonQualifiedDeferredCompensationPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Nonqualified Deferred Compensation Plan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NonQualifiedDeferredCompensationPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Non Qualified Deferred Compensation Plan [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:type="locator" xlink:label="us-gaap_RetirementPlanSponsorLocationAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RetirementPlanSponsorLocationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Retirement Plan Sponsor Location</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetirementPlanSponsorLocationAxis" xlink:to="us-gaap_RetirementPlanSponsorLocationAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RetirementPlanSponsorLocationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Retirement Plan Sponsor Location [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:type="locator" xlink:label="us-gaap_RetirementPlanSponsorLocationDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RetirementPlanSponsorLocationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Retirement Plan Sponsor Location</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetirementPlanSponsorLocationDomain" xlink:to="us-gaap_RetirementPlanSponsorLocationDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RetirementPlanSponsorLocationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Retirement Plan Sponsor Location [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember" xlink:type="locator" xlink:label="us-gaap_ForeignPlanMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign Retirement Plans [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignPlanMember" xlink:to="us-gaap_ForeignPlanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Plan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ExpectedPeriodOfReturnOnPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected period of return on plan assets, years</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ExpectedPeriodOfReturnOnPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Expected Period Of Return On Plan Assets</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel1Member" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 1 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel1Member" xlink:to="us-gaap_FairValueInputsLevel1Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Inputs Level1 [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel2Member" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 2 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel2Member" xlink:to="us-gaap_FairValueInputsLevel2Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Inputs Level2 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total fair value</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DefinedBenefitPlansUnrealizedGainsLosses" xlink:type="locator" xlink:label="ajg_DefinedBenefitPlansUnrealizedGainsLosses" />
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlansUnrealizedGainsLosses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined benefit plans, unrealized gains losses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DefinedBenefitPlansUnrealizedGainsLosses" xlink:to="ajg_DefinedBenefitPlansUnrealizedGainsLosses_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanSettlementsPlanAssets" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanSettlementsPlanAssets" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanSettlementsPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Settlements</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanSettlementsPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanSettlementsPlanAssets_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanSettlementsPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Settlements Plan Assets</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlansUnrealizedGainsLosses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrealized gain</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlansUnrealizedGainsLosses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plans Unrealized Gains Losses</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanContributionsByEmployer" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanContributionsByEmployer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum contribution by employer</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:to="us-gaap_DefinedBenefitPlanContributionsByEmployer_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanContributionsByEmployer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Contributions By Employer</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Discretionary contributions by employer</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DefinedBenefitPlanPercentageOfEligibleCompensationForMatchingContributionsByEmployer" xlink:type="locator" xlink:label="ajg_DefinedBenefitPlanPercentageOfEligibleCompensationForMatchingContributionsByEmployer" />
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlanPercentageOfEligibleCompensationForMatchingContributionsByEmployer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined benefit plan percentage of eligible compensation for matching contributions by employer.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DefinedBenefitPlanPercentageOfEligibleCompensationForMatchingContributionsByEmployer" xlink:to="ajg_DefinedBenefitPlanPercentageOfEligibleCompensationForMatchingContributionsByEmployer_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_MatchingContributionsVestingSchedule" xlink:type="locator" xlink:label="ajg_MatchingContributionsVestingSchedule" />
    <link:label xml:lang="en-US" xlink:label="ajg_MatchingContributionsVestingSchedule_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Matching contributions vesting schedule.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_MatchingContributionsVestingSchedule" xlink:to="ajg_MatchingContributionsVestingSchedule_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" xlink:type="locator" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Matching contributions by employer, percentage</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" xlink:to="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Contribution Plan Employer Matching Contribution Percent</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlanPercentageOfEligibleCompensationForMatchingContributionsByEmployer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of eligible compensation for matching contributions by employer</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlanPercentageOfEligibleCompensationForMatchingContributionsByEmployer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Percentage Of Eligible Compensation For Matching Contributions By Employer</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_MatchingContributionsVestingSchedule_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Matching contributions vesting schedule</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_MatchingContributionsVestingSchedule_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Matching Contributions Vesting Schedule</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanCostRecognized" xlink:type="locator" xlink:label="us-gaap_DefinedContributionPlanCostRecognized" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanCostRecognized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contribution expense to plan</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanCostRecognized" xlink:to="us-gaap_DefinedContributionPlanCostRecognized_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanCostRecognized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Contribution Plan Cost Recognized</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Fair value of plan assets</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DefinedBenefitPlanAdditionalPercentageOfEligibleCompensationForMatchingContributionsByEmployer" xlink:type="locator" xlink:label="ajg_DefinedBenefitPlanAdditionalPercentageOfEligibleCompensationForMatchingContributionsByEmployer" />
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlanAdditionalPercentageOfEligibleCompensationForMatchingContributionsByEmployer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined benefit plan, additional percentage of eligible compensation for matching contributions by employer</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DefinedBenefitPlanAdditionalPercentageOfEligibleCompensationForMatchingContributionsByEmployer" xlink:to="ajg_DefinedBenefitPlanAdditionalPercentageOfEligibleCompensationForMatchingContributionsByEmployer_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlanAdditionalPercentageOfEligibleCompensationForMatchingContributionsByEmployer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional percentage of eligible compensation for matching contributions by employer</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DefinedBenefitPlanAdditionalPercentageOfEligibleCompensationForMatchingContributionsByEmployer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Additional Percentage Of Eligible Compensation For Matching Contributions By Employer</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_EquityMethodInvestmentSummarizedFinancialInformationFundingCommitments" xlink:type="locator" xlink:label="ajg_EquityMethodInvestmentSummarizedFinancialInformationFundingCommitments" />
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentSummarizedFinancialInformationFundingCommitments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity Method Investment Summarized Financial Information Funding Commitments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_EquityMethodInvestmentSummarizedFinancialInformationFundingCommitments" xlink:to="ajg_EquityMethodInvestmentSummarizedFinancialInformationFundingCommitments_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Equity Method Investments [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEquityMethodInvestmentsTable" xlink:to="us-gaap_ScheduleOfEquityMethodInvestmentsTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Equity Method Investments [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:type="locator" xlink:label="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment, Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:to="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Equity Method Investment Equity Method Investee Name [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_EquityMethodInvesteeNameDomain" xlink:type="locator" xlink:label="srt_EquityMethodInvesteeNameDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_EquityMethodInvesteeNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment, Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_EquityMethodInvesteeNameDomain" xlink:to="srt_EquityMethodInvesteeNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_EquityMethodInvesteeNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investee Name [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ChemModLLCMember" xlink:type="locator" xlink:label="ajg_ChemModLLCMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Chem mod LLC.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ChemModLLCMember" xlink:to="ajg_ChemModLLCMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Chem-Mod LLC [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Chem Mod L L C [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ChemModInternationalLlcMember" xlink:type="locator" xlink:label="ajg_ChemModInternationalLlcMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModInternationalLlcMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Chem mod international llc.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ChemModInternationalLlcMember" xlink:to="ajg_ChemModInternationalLlcMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModInternationalLlcMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Chem-Mod International LLC [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModInternationalLlcMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Chem Mod International Llc [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CleanCoalInvestmentsMember" xlink:type="locator" xlink:label="ajg_CleanCoalInvestmentsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CleanCoalInvestmentsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Clean-coal investments.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CleanCoalInvestmentsMember" xlink:to="ajg_CleanCoalInvestmentsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CleanCoalInvestmentsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Clean-Coal Investments [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CleanCoalInvestmentsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Clean Coal Investments [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_VentureCapitalFundsAndOtherMember" xlink:type="locator" xlink:label="ajg_VentureCapitalFundsAndOtherMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_VentureCapitalFundsAndOtherMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Venture capital funds and other.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_VentureCapitalFundsAndOtherMember" xlink:to="ajg_VentureCapitalFundsAndOtherMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_VentureCapitalFundsAndOtherMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Investments [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_VentureCapitalFundsAndOtherMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Venture Capital Funds And Other [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ControllingInterestMember" xlink:type="locator" xlink:label="ajg_ControllingInterestMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_ControllingInterestMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Controlling interest.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ControllingInterestMember" xlink:to="ajg_ControllingInterestMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ControllingInterestMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Controlling Interest [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ControllingInterestMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Controlling Interest [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FourteenTwoThousandNineEraCleanCoalProductionPlantsMember" xlink:type="locator" xlink:label="ajg_FourteenTwoThousandNineEraCleanCoalProductionPlantsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FourteenTwoThousandNineEraCleanCoalProductionPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fourteen two thousand nine era clean coal production plants.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FourteenTwoThousandNineEraCleanCoalProductionPlantsMember" xlink:to="ajg_FourteenTwoThousandNineEraCleanCoalProductionPlantsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FourteenTwoThousandNineEraCleanCoalProductionPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fourteen 2009 Era Clean Coal Plants [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FourteenTwoThousandNineEraCleanCoalProductionPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fourteen Two Thousand Nine Era Clean Coal Production Plants [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_OneTwoThousandElevenEraCleanCoalProductionPlantsMember" xlink:type="locator" xlink:label="ajg_OneTwoThousandElevenEraCleanCoalProductionPlantsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_OneTwoThousandElevenEraCleanCoalProductionPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">One two thousand eleven era clean coal production plant.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_OneTwoThousandElevenEraCleanCoalProductionPlantsMember" xlink:to="ajg_OneTwoThousandElevenEraCleanCoalProductionPlantsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_OneTwoThousandElevenEraCleanCoalProductionPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">One 2011 Era Clean Coal Plant [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_OneTwoThousandElevenEraCleanCoalProductionPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">One Two Thousand Eleven Era Clean Coal Production Plants [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwentyTwoThousandElevenEraCleanCoalProductionPlantsMember" xlink:type="locator" xlink:label="ajg_TwentyTwoThousandElevenEraCleanCoalProductionPlantsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwentyTwoThousandElevenEraCleanCoalProductionPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Twenty two thousand eleven era clean coal production plants.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwentyTwoThousandElevenEraCleanCoalProductionPlantsMember" xlink:to="ajg_TwentyTwoThousandElevenEraCleanCoalProductionPlantsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwentyTwoThousandElevenEraCleanCoalProductionPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Twenty 2011 Era Clean Coal Plants [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwentyTwoThousandElevenEraCleanCoalProductionPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Twenty Two Thousand Eleven Era Clean Coal Production Plants [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:type="locator" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Equity Method Investments [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:to="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Equity Method Investments [Line Items]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityMethodInvestments" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestments" xlink:to="us-gaap_EquityMethodInvestments_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investments</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentSummarizedFinancialInformationFundingCommitments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Funding commitments</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentSummarizedFinancialInformationFundingCommitments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Summarized Financial Information Funding Commitments</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfCoalPlants" xlink:type="locator" xlink:label="ajg_NumberOfCoalPlants" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCoalPlants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of Coal Plants</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfCoalPlants" xlink:to="ajg_NumberOfCoalPlants_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCoalPlants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of coal plants</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCoalPlants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Coal Plants</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ChemModCleanCoalVentureUsAndCanadianOperationsMember" xlink:type="locator" xlink:label="ajg_ChemModCleanCoalVentureUsAndCanadianOperationsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModCleanCoalVentureUsAndCanadianOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Chem-Mod Clean-Coal Venture - US and Canadian Operations [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ChemModCleanCoalVentureUsAndCanadianOperationsMember" xlink:to="ajg_ChemModCleanCoalVentureUsAndCanadianOperationsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModCleanCoalVentureUsAndCanadianOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Chem-Mod Clean-Coal Venture - U.S. and Canadian Operations [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModCleanCoalVentureUsAndCanadianOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Chem Mod Clean Coal Venture Us And Canadian Operations [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ChemModCleanCoalVentureMember" xlink:type="locator" xlink:label="ajg_ChemModCleanCoalVentureMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModCleanCoalVentureMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Chem-Mod Clean-Coal Venture [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ChemModCleanCoalVentureMember" xlink:to="ajg_ChemModCleanCoalVentureMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModCleanCoalVentureMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Chem-Mod Clean-Coal Venture [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ChemModCleanCoalVentureMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Chem Mod Clean Coal Venture [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidatedEntitiesAxis" xlink:type="locator" xlink:label="srt_ConsolidatedEntitiesAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_ConsolidatedEntitiesAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidated Entities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ConsolidatedEntitiesAxis" xlink:to="srt_ConsolidatedEntitiesAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ConsolidatedEntitiesAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Consolidated Entities [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidatedEntitiesDomain" xlink:type="locator" xlink:label="srt_ConsolidatedEntitiesDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_ConsolidatedEntitiesDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidated Entities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ConsolidatedEntitiesDomain" xlink:to="srt_ConsolidatedEntitiesDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ConsolidatedEntitiesDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Consolidated Entities [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember" xlink:type="locator" xlink:label="us-gaap_VariableInterestEntityPrimaryBeneficiaryMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">VIE [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableInterestEntityPrimaryBeneficiaryMember" xlink:to="us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Variable Interest Entity Primary Beneficiary [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CQuestCleanCoalVentureGlobalOperationsMember" xlink:type="locator" xlink:label="ajg_CQuestCleanCoalVentureGlobalOperationsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CQuestCleanCoalVentureGlobalOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">C-Quest Clean-Coal Venture Global Operations [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CQuestCleanCoalVentureGlobalOperationsMember" xlink:to="ajg_CQuestCleanCoalVentureGlobalOperationsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CQuestCleanCoalVentureGlobalOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Chem-Mod International LLC [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CQuestCleanCoalVentureGlobalOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">C Quest Clean Coal Venture Global Operations [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember" xlink:type="locator" xlink:label="us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Variable Interest Entity, Not Primary Beneficiary [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember" xlink:to="us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Variable Interest Entity Not Primary Beneficiary [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveTerseLabel">Ownership interest held</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_EquityMethodInvestmentRevenuesOfLimitedLiabilityCompanies" xlink:type="locator" xlink:label="ajg_EquityMethodInvestmentRevenuesOfLimitedLiabilityCompanies" />
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentRevenuesOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity Method Investment Total Revenues Of Limited Liability Companies.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_EquityMethodInvestmentRevenuesOfLimitedLiabilityCompanies" xlink:to="ajg_EquityMethodInvestmentRevenuesOfLimitedLiabilityCompanies_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_EquityMethodInvestmentExpensesOfLimitedLiabilityCompanies" xlink:type="locator" xlink:label="ajg_EquityMethodInvestmentExpensesOfLimitedLiabilityCompanies" />
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentExpensesOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity Method Investment Total Expenses Of Limited Liability Companies.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_EquityMethodInvestmentExpensesOfLimitedLiabilityCompanies" xlink:to="ajg_EquityMethodInvestmentExpensesOfLimitedLiabilityCompanies_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Assets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total assets of variable interest entities</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_Liabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total liabilities of variable interest entities</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentRevenuesOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total revenues of limited liability companies</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentRevenuesOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Revenues Of Limited Liability Companies</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentExpensesOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total expenses of limited liability companies</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentExpensesOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Expenses Of Limited Liability Companies</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_VariableInterestEntityOwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveTerseLabel">Ownership interest held</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfCleanCoalProductionPlantsOwned" xlink:type="locator" xlink:label="ajg_NumberOfCleanCoalProductionPlantsOwned" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCleanCoalProductionPlantsOwned_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of clean coal production plants owned</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfCleanCoalProductionPlantsOwned" xlink:to="ajg_NumberOfCleanCoalProductionPlantsOwned_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandNineEraPlantsMember" xlink:type="locator" xlink:label="ajg_TwoThousandNineEraPlantsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandNineEraPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Nine Era Plants [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandNineEraPlantsMember" xlink:to="ajg_TwoThousandNineEraPlantsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandNineEraPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2009 Era Plants [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandNineEraPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Nine Era Plants [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TwoThousandElevenEraPlantsMember" xlink:type="locator" xlink:label="ajg_TwoThousandElevenEraPlantsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandElevenEraPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Eleven Era Plants [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TwoThousandElevenEraPlantsMember" xlink:to="ajg_TwoThousandElevenEraPlantsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandElevenEraPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2011 Era Plants [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TwoThousandElevenEraPlantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Eleven Era Plants [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_LongTermProductionContractsMember" xlink:type="locator" xlink:label="ajg_LongTermProductionContractsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_LongTermProductionContractsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Long Term Production Contracts [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_LongTermProductionContractsMember" xlink:to="ajg_LongTermProductionContractsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_LongTermProductionContractsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long Term Production Contracts [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_LongTermProductionContractsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Production Contracts [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCleanCoalProductionPlantsOwned_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of clean coal production plants owned</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCleanCoalProductionPlantsOwned_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Clean Coal Production Plants Owned</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfVariableInterestEntities" xlink:type="locator" xlink:label="ajg_NumberOfVariableInterestEntities" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfVariableInterestEntities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of Variable Interest Entities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfVariableInterestEntities" xlink:to="ajg_NumberOfVariableInterestEntities_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_EquityMethodInvestmentAssetsOfLimitedLiabilityCompanies" xlink:type="locator" xlink:label="ajg_EquityMethodInvestmentAssetsOfLimitedLiabilityCompanies" />
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentAssetsOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity Method Investment Total Assets Of Limited Liability Companies</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_EquityMethodInvestmentAssetsOfLimitedLiabilityCompanies" xlink:to="ajg_EquityMethodInvestmentAssetsOfLimitedLiabilityCompanies_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_EquityMethodInvestmentLiabilitiesOfLimitedLiabilityCompanies" xlink:type="locator" xlink:label="ajg_EquityMethodInvestmentLiabilitiesOfLimitedLiabilityCompanies" />
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentLiabilitiesOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity Method Investment Total Liabilities Of Limited Liability Companies.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_EquityMethodInvestmentLiabilitiesOfLimitedLiabilityCompanies" xlink:to="ajg_EquityMethodInvestmentLiabilitiesOfLimitedLiabilityCompanies_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfVariableInterestEntities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of variable interest entities</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfVariableInterestEntities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Variable Interest Entities</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentAssetsOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total assets of limited liability companies</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentAssetsOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Assets Of Limited Liability Companies</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentLiabilitiesOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total liability of limited liability companies</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EquityMethodInvestmentLiabilitiesOfLimitedLiabilityCompanies_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Liabilities Of Limited Liability Companies</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfVentureCapitalFundsInvestment" xlink:type="locator" xlink:label="ajg_NumberOfVentureCapitalFundsInvestment" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfVentureCapitalFundsInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number Of Venture Capital Funds Investment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfVentureCapitalFundsInvestment" xlink:to="ajg_NumberOfVentureCapitalFundsInvestment_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfCertifiedLowIncomeHousingDevelopmentsInvestment" xlink:type="locator" xlink:label="ajg_NumberOfCertifiedLowIncomeHousingDevelopmentsInvestment" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCertifiedLowIncomeHousingDevelopmentsInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number Of Certified Low Income Housing Developments Investment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfCertifiedLowIncomeHousingDevelopmentsInvestment" xlink:to="ajg_NumberOfCertifiedLowIncomeHousingDevelopmentsInvestment_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CarryingValueOfInvestments" xlink:type="locator" xlink:label="ajg_CarryingValueOfInvestments" />
    <link:label xml:lang="en-US" xlink:label="ajg_CarryingValueOfInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Carrying Value of Investments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CarryingValueOfInvestments" xlink:to="ajg_CarryingValueOfInvestments_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_Investment1Axis" xlink:type="locator" xlink:label="ajg_Investment1Axis" />
    <link:label xml:lang="en-US" xlink:label="ajg_Investment1Axis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment1</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_Investment1Axis" xlink:to="ajg_Investment1Axis_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_Investment1Axis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investment1 [Axis]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_Investment1Domain" xlink:type="locator" xlink:label="ajg_Investment1Domain" />
    <link:label xml:lang="en-US" xlink:label="ajg_Investment1Domain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment1</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_Investment1Domain" xlink:to="ajg_Investment1Domain_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_Investment1Domain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investment1 [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FourVentureCapitalFundsMember" xlink:type="locator" xlink:label="ajg_FourVentureCapitalFundsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FourVentureCapitalFundsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Four Venture Capital Funds [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FourVentureCapitalFundsMember" xlink:to="ajg_FourVentureCapitalFundsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FourVentureCapitalFundsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Four Venture Capital Funds [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FourVentureCapitalFundsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Four Venture Capital Funds [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_EightCertifiedLowIncomeHousingDevelopmentsMember" xlink:type="locator" xlink:label="ajg_EightCertifiedLowIncomeHousingDevelopmentsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_EightCertifiedLowIncomeHousingDevelopmentsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Eight certified low income housing developments.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_EightCertifiedLowIncomeHousingDevelopmentsMember" xlink:to="ajg_EightCertifiedLowIncomeHousingDevelopmentsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_EightCertifiedLowIncomeHousingDevelopmentsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Eight Certified Low Income Housing Developments [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EightCertifiedLowIncomeHousingDevelopmentsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Eight Certified Low Income Housing Developments [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfVentureCapitalFundsInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non controlling interest in venture capital funds number</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfVentureCapitalFundsInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Venture Capital Funds Investment</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCertifiedLowIncomeHousingDevelopmentsInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non controlling interest certified low-income housing developments</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfCertifiedLowIncomeHousingDevelopmentsInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Certified Low Income Housing Developments Investment</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CarryingValueOfInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Carrying value of investments</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CarryingValueOfInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Carrying Value Of Investments</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:type="locator" xlink:label="us-gaap_IncomeStatementLocationAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementLocationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Statement Location</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementLocationAxis" xlink:to="us-gaap_IncomeStatementLocationAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementLocationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement Location [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:type="locator" xlink:label="us-gaap_IncomeStatementLocationDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementLocationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Statement Location</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementLocationDomain" xlink:to="us-gaap_IncomeStatementLocationDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementLocationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement Location [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingExpenseMember" xlink:type="locator" xlink:label="us-gaap_OperatingExpenseMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingExpenseMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpenseMember" xlink:to="us-gaap_OperatingExpenseMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingExpenseMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Expense [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentIncomeMember" xlink:type="locator" xlink:label="us-gaap_InvestmentIncomeMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentIncomeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment Income [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentIncomeMember" xlink:to="us-gaap_InvestmentIncomeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentIncomeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investment Income [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseCost" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseCost" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseCost" xlink:to="us-gaap_OperatingLeaseCost_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Cost</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableLeaseCost" xlink:type="locator" xlink:label="us-gaap_VariableLeaseCost" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_VariableLeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Variable lease expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableLeaseCost" xlink:to="us-gaap_VariableLeaseCost_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_VariableLeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Variable Lease Cost</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubleaseIncome" xlink:type="locator" xlink:label="us-gaap_SubleaseIncome" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SubleaseIncome_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Sublease income</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubleaseIncome" xlink:to="us-gaap_SubleaseIncome_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SubleaseIncome_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sublease Income</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LeaseCost" xlink:type="locator" xlink:label="us-gaap_LeaseCost" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total net lease expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCost" xlink:to="us-gaap_LeaseCost_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lease Cost</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract" xlink:type="locator" xlink:label="ajg_CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract" />
    <link:label xml:lang="en-US" xlink:label="ajg_CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash paid for amounts included in measurement of lease liabilities.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract" xlink:to="ajg_CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash paid for amounts included in the measurement of lease liabilities:</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash Paid For Amounts Included In Measurement Of Lease Liabilities [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeasePayments" xlink:type="locator" xlink:label="us-gaap_OperatingLeasePayments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeasePayments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating cash flows from operating leases</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasePayments" xlink:to="us-gaap_OperatingLeasePayments_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeasePayments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Payments</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:type="locator" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use assets obtained in exchange for new operating lease liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:to="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Right Of Use Asset Obtained In Exchange For Operating Lease Liability</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveTerseLabel">Lease right-of-use assets</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current lease liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityCurrent" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Liability Current</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList" xlink:to="us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Liability Current Statement Of Financial Position Extensible List</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Lease liabilities</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total lease liabilities</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Weighted-average remaining lease term, years</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Weighted Average Remaining Lease Term1</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average discount rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:to="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Weighted Average Discount Rate Percent</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2021</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due Next Twelve Months</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2022</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due Year Two</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due Year Three</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due Year Four</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due Year Five</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Thereafter</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due After Year Five</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total lease payments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Less interest</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Undiscounted Excess Amount</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseRemainingLeaseTerm" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease, remaining lease term</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm" xlink:to="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Remaining Lease Term</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseOptionToExtend" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseOptionToExtend" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseOptionToExtend_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lessee, operating lease, option to extend</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseOptionToExtend" xlink:to="us-gaap_LesseeOperatingLeaseOptionToExtend_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseOptionToExtend_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Option To Extend</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_OperatingLeaseLiabilityNotYetCommenced" xlink:type="locator" xlink:label="ajg_OperatingLeaseLiabilityNotYetCommenced" />
    <link:label xml:lang="en-US" xlink:label="ajg_OperatingLeaseLiabilityNotYetCommenced_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents operating lease liability not yet commenced.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_OperatingLeaseLiabilityNotYetCommenced" xlink:to="ajg_OperatingLeaseLiabilityNotYetCommenced_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_OperatingLeaseLiabilityNotYetCommenced_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease liability not yet commenced</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_OperatingLeaseLiabilityNotYetCommenced_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Liability Not Yet Commenced</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lessee, operating lease, lease not yet commenced, term of contract</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1" xlink:to="us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Lease Not Yet Commenced Term Of Contract1</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NotionalAmountOfDerivativesAbstract" xlink:type="locator" xlink:label="us-gaap_NotionalAmountOfDerivativesAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NotionalAmountOfDerivativesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Notional Amount Of Derivatives [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotionalAmountOfDerivativesAbstract" xlink:to="us-gaap_NotionalAmountOfDerivativesAbstract_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:type="locator" xlink:label="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:to="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentRiskAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeInstrumentRiskAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative Instrument</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeInstrumentRiskAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeInstrumentRiskAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instrument Risk [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:type="locator" xlink:label="us-gaap_DerivativeContractTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeContractTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative Contract</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_DerivativeContractTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeContractTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Contract Type [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestRateContractMember" xlink:type="locator" xlink:label="us-gaap_InterestRateContractMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestRateContractMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest Rate Contracts [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestRateContractMember" xlink:to="us-gaap_InterestRateContractMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestRateContractMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Rate Contract [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeContractMember" xlink:type="locator" xlink:label="us-gaap_ForeignExchangeContractMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignExchangeContractMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign Exchange Contracts [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignExchangeContractMember" xlink:to="us-gaap_ForeignExchangeContractMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignExchangeContractMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Exchange Contract [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:type="locator" xlink:label="us-gaap_BalanceSheetLocationAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Balance Sheet Location</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetLocationAxis" xlink:to="us-gaap_BalanceSheetLocationAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Balance Sheet Location [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:type="locator" xlink:label="us-gaap_BalanceSheetLocationDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Balance Sheet Location</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetLocationDomain" xlink:to="us-gaap_BalanceSheetLocationDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Balance Sheet Location [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCurrentAssetsMember" xlink:type="locator" xlink:label="us-gaap_OtherCurrentAssetsMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherCurrentAssetsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current Assets [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCurrentAssetsMember" xlink:to="us-gaap_OtherCurrentAssetsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherCurrentAssetsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Current Assets [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNoncurrentAssetsMember" xlink:type="locator" xlink:label="us-gaap_OtherNoncurrentAssetsMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherNoncurrentAssetsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other noncurrent Assets [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNoncurrentAssetsMember" xlink:to="us-gaap_OtherNoncurrentAssetsMember_lbl" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeMember" xlink:type="locator" xlink:label="us-gaap_ForeignExchangeMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignExchangeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign Exchange [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignExchangeMember" xlink:to="us-gaap_ForeignExchangeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignExchangeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Exchange [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Other comprehensive income (loss), foreign currency transaction and translation adjustment, net of tax</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementScenarioAxis" xlink:type="locator" xlink:label="srt_StatementScenarioAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_StatementScenarioAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Scenario</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_StatementScenarioAxis" xlink:to="srt_StatementScenarioAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_StatementScenarioAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Scenario [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScenarioUnspecifiedDomain" xlink:type="locator" xlink:label="srt_ScenarioUnspecifiedDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_ScenarioUnspecifiedDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Scenario</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScenarioUnspecifiedDomain" xlink:to="srt_ScenarioUnspecifiedDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ScenarioUnspecifiedDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Scenario Unspecified [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScenarioForecastMember" xlink:type="locator" xlink:label="srt_ScenarioForecastMember" />
    <link:label xml:lang="en-US" xlink:label="srt_ScenarioForecastMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Scenario, Forecast [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScenarioForecastMember" xlink:to="srt_ScenarioForecastMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ScenarioForecastMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Scenario Forecast [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred" xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Estimated pretax loss to be reclassified from accumulated other comprehensive loss into earnings</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred" xlink:to="us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instruments Gain Loss Reclassification From Accumulated O C I To Income Estimated Net Amount To Be Transferred</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsLineItems" xlink:type="locator" xlink:label="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsLineItems" />
    <link:label xml:lang="en-US" xlink:label="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsLineItems" xlink:to="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsLineItems_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsTable" xlink:type="locator" xlink:label="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsTable" />
    <link:label xml:lang="en-US" xlink:label="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Commitments Contingencies And Off Balance Sheet Arrangements [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsTable" xlink:to="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments Contingencies And Off Balance Sheet Arrangements [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Commitments Contingencies And Off Balance Sheet Arrangements [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis" xlink:type="locator" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recorded Unconditional Purchase Obligation by Category of Item Purchased</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis" xlink:to="us-gaap_RecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation By Category Of Item Purchased [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnconditionalPurchaseObligationCategoryOfGoodsOrServicesAcquiredDomain" xlink:type="locator" xlink:label="us-gaap_UnconditionalPurchaseObligationCategoryOfGoodsOrServicesAcquiredDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnconditionalPurchaseObligationCategoryOfGoodsOrServicesAcquiredDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unconditional Purchase Obligation, Category of Goods or Services Acquired</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnconditionalPurchaseObligationCategoryOfGoodsOrServicesAcquiredDomain" xlink:to="us-gaap_UnconditionalPurchaseObligationCategoryOfGoodsOrServicesAcquiredDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnconditionalPurchaseObligationCategoryOfGoodsOrServicesAcquiredDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unconditional Purchase Obligation Category Of Goods Or Services Acquired [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_InterestOnDebtMember" xlink:type="locator" xlink:label="ajg_InterestOnDebtMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterestOnDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest On Debt [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_InterestOnDebtMember" xlink:to="ajg_InterestOnDebtMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_InterestOnDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest On Debt [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_InterestOnDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest On Debt [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DebtObligationMember" xlink:type="locator" xlink:label="ajg_DebtObligationMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_DebtObligationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt Obligation [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DebtObligationMember" xlink:to="ajg_DebtObligationMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_DebtObligationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total Debt Obligations [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_DebtObligationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Obligation [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_OperatingLeaseObligationMember" xlink:type="locator" xlink:label="ajg_OperatingLeaseObligationMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_OperatingLeaseObligationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Operating Lease Obligation [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_OperatingLeaseObligationMember" xlink:to="ajg_OperatingLeaseObligationMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_OperatingLeaseObligationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Lease Obligations [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_OperatingLeaseObligationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Obligation [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_SubleaseArrangementsMember" xlink:type="locator" xlink:label="ajg_SubleaseArrangementsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_SubleaseArrangementsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Sublease arrangements.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_SubleaseArrangementsMember" xlink:to="ajg_SubleaseArrangementsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_SubleaseArrangementsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less Sublease Arrangements [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_SubleaseArrangementsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sublease Arrangements [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_OutstandingPurchaseObligationsMember" xlink:type="locator" xlink:label="ajg_OutstandingPurchaseObligationsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_OutstandingPurchaseObligationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Outstanding purchase obligations.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_OutstandingPurchaseObligationsMember" xlink:to="ajg_OutstandingPurchaseObligationsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_OutstandingPurchaseObligationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Outstanding Purchase Obligations [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_OutstandingPurchaseObligationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Outstanding Purchase Obligations [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ContractualObligationsMember" xlink:type="locator" xlink:label="ajg_ContractualObligationsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_ContractualObligationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Contractual Obligations [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ContractualObligationsMember" xlink:to="ajg_ContractualObligationsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ContractualObligationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total Contractual Obligations [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ContractualObligationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contractual Obligations [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CommitmentsContingenciesAndOffBalanceSheetArrangementsLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RecordedUnconditionalPurchaseObligationDueWithinOneYear" xlink:type="locator" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueWithinOneYear" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueWithinOneYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractual Obligations, Payments Due by Period, 2021</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RecordedUnconditionalPurchaseObligationDueWithinOneYear" xlink:to="us-gaap_RecordedUnconditionalPurchaseObligationDueWithinOneYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueWithinOneYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Due Within One Year</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RecordedUnconditionalPurchaseObligationReceivableWithinOneYear" xlink:type="locator" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableWithinOneYear" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableWithinOneYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Recorded unconditional purchase obligation receivable within one year.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RecordedUnconditionalPurchaseObligationReceivableWithinOneYear" xlink:to="ajg_RecordedUnconditionalPurchaseObligationReceivableWithinOneYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableWithinOneYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Contractual Obligations, Payments Receivable by Period, 2021</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableWithinOneYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Receivable Within One Year</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RecordedUnconditionalPurchaseObligationDueInSecondYear" xlink:type="locator" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInSecondYear" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInSecondYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractual Obligations, Payments Due by Period, 2022</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RecordedUnconditionalPurchaseObligationDueInSecondYear" xlink:to="us-gaap_RecordedUnconditionalPurchaseObligationDueInSecondYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInSecondYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Due In Second Year</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RecordedUnconditionalPurchaseObligationReceivableInSecondYear" xlink:type="locator" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInSecondYear" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInSecondYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Recorded unconditional purchase obligation receivable in second year.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RecordedUnconditionalPurchaseObligationReceivableInSecondYear" xlink:to="ajg_RecordedUnconditionalPurchaseObligationReceivableInSecondYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInSecondYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Contractual Obligations, Payments Receivable by Period, 2022</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInSecondYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Receivable In Second Year</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RecordedUnconditionalPurchaseObligationDueInThirdYear" xlink:type="locator" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInThirdYear" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInThirdYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractual Obligations, Payments Due by Period, 2023</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RecordedUnconditionalPurchaseObligationDueInThirdYear" xlink:to="us-gaap_RecordedUnconditionalPurchaseObligationDueInThirdYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInThirdYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Due In Third Year</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RecordedUnconditionalPurchaseObligationReceivableInThirdYear" xlink:type="locator" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInThirdYear" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInThirdYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Recorded unconditional purchase obligation receivable in third year.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RecordedUnconditionalPurchaseObligationReceivableInThirdYear" xlink:to="ajg_RecordedUnconditionalPurchaseObligationReceivableInThirdYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInThirdYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Contractual Obligations, Payments Receivable by Period, 2023</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInThirdYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Receivable In Third Year</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RecordedUnconditionalPurchaseObligationDueInFourthYear" xlink:type="locator" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInFourthYear" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInFourthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractual Obligations, Payments Due by Period, 2024</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RecordedUnconditionalPurchaseObligationDueInFourthYear" xlink:to="us-gaap_RecordedUnconditionalPurchaseObligationDueInFourthYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInFourthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Due In Fourth Year</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RecordedUnconditionalPurchaseObligationReceivableInFourthYear" xlink:type="locator" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInFourthYear" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInFourthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Recorded unconditional purchase obligation receivable in fourth year.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RecordedUnconditionalPurchaseObligationReceivableInFourthYear" xlink:to="ajg_RecordedUnconditionalPurchaseObligationReceivableInFourthYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInFourthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Contractual Obligations, Payments Receivable by Period, 2024</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInFourthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Receivable In Fourth Year</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RecordedUnconditionalPurchaseObligationDueInFifthYear" xlink:type="locator" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInFifthYear" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInFifthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractual Obligations, Payments Due by Period, 2025</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RecordedUnconditionalPurchaseObligationDueInFifthYear" xlink:to="us-gaap_RecordedUnconditionalPurchaseObligationDueInFifthYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueInFifthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Due In Fifth Year</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RecordedUnconditionalPurchaseObligationReceivableInFifthYear" xlink:type="locator" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInFifthYear" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInFifthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Recorded unconditional purchase obligation receivable in fifth year.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RecordedUnconditionalPurchaseObligationReceivableInFifthYear" xlink:to="ajg_RecordedUnconditionalPurchaseObligationReceivableInFifthYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInFifthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Contractual Obligations, Payments Receivable by Period, 2025</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableInFifthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Receivable In Fifth Year</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RecordedUnconditionalPurchaseObligationDueAfterFifthYear" xlink:type="locator" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueAfterFifthYear" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueAfterFifthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractual Obligations, Payments Due by Period, Thereafter</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RecordedUnconditionalPurchaseObligationDueAfterFifthYear" xlink:to="us-gaap_RecordedUnconditionalPurchaseObligationDueAfterFifthYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligationDueAfterFifthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Due After Fifth Year</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RecordedUnconditionalPurchaseObligationReceivableAfterFifthYear" xlink:type="locator" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableAfterFifthYear" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableAfterFifthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Recorded unconditional purchase obligation receivable after fifth year.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RecordedUnconditionalPurchaseObligationReceivableAfterFifthYear" xlink:to="ajg_RecordedUnconditionalPurchaseObligationReceivableAfterFifthYear_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableAfterFifthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Contractual Obligations, Payments Receivable by Period, Thereafter</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivableAfterFifthYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Receivable After Fifth Year</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RecordedUnconditionalPurchaseObligation" xlink:type="locator" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligation" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Contractual Obligations, Payments Due by Period, Total</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RecordedUnconditionalPurchaseObligation" xlink:to="us-gaap_RecordedUnconditionalPurchaseObligation_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecordedUnconditionalPurchaseObligation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RecordedUnconditionalPurchaseObligationReceivable" xlink:type="locator" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivable" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Recorded unconditional purchase obligation receivable.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RecordedUnconditionalPurchaseObligationReceivable" xlink:to="ajg_RecordedUnconditionalPurchaseObligationReceivable_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Contractual Obligations, Payments Receivable by Period, Total</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RecordedUnconditionalPurchaseObligationReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recorded Unconditional Purchase Obligation Receivable</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_TaxIncrementFinancingMember" xlink:type="locator" xlink:label="ajg_TaxIncrementFinancingMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_TaxIncrementFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Tax Increment Financing [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_TaxIncrementFinancingMember" xlink:to="ajg_TaxIncrementFinancingMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_TaxIncrementFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tax Increment Financing [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_TaxIncrementFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Tax Increment Financing [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UnconsolidatedInvestmentsInEnterprisesMember" xlink:type="locator" xlink:label="ajg_UnconsolidatedInvestmentsInEnterprisesMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_UnconsolidatedInvestmentsInEnterprisesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Unconsolidated investments in enterprises.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UnconsolidatedInvestmentsInEnterprisesMember" xlink:to="ajg_UnconsolidatedInvestmentsInEnterprisesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_UnconsolidatedInvestmentsInEnterprisesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unconsolidated Investments in Enterprises [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UnconsolidatedInvestmentsInEnterprisesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unconsolidated Investments In Enterprises [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShortTermDebtTypeAxis" xlink:type="locator" xlink:label="us-gaap_ShortTermDebtTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShortTermDebtTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short-term Debt, Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermDebtTypeAxis" xlink:to="us-gaap_ShortTermDebtTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShortTermDebtTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Short Term Debt Type [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShortTermDebtTypeDomain" xlink:type="locator" xlink:label="us-gaap_ShortTermDebtTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShortTermDebtTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short-term Debt, Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermDebtTypeDomain" xlink:to="us-gaap_ShortTermDebtTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShortTermDebtTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Short Term Debt Type [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LetterOfCreditMember" xlink:type="locator" xlink:label="us-gaap_LetterOfCreditMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LetterOfCreditMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Letter of Credit [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LetterOfCreditMember" xlink:to="us-gaap_LetterOfCreditMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LetterOfCreditMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Letter Of Credit [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_SelfInsuranceDeductiblesMember" xlink:type="locator" xlink:label="ajg_SelfInsuranceDeductiblesMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_SelfInsuranceDeductiblesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Self-Insurance Deductibles [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_SelfInsuranceDeductiblesMember" xlink:to="ajg_SelfInsuranceDeductiblesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_SelfInsuranceDeductiblesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Self-Insurance Deductibles [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_SelfInsuranceDeductiblesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Self Insurance Deductibles [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_RentCaptiveFacilityMember" xlink:type="locator" xlink:label="ajg_RentCaptiveFacilityMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_RentCaptiveFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Rent-a-captive Facility [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_RentCaptiveFacilityMember" xlink:to="ajg_RentCaptiveFacilityMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_RentCaptiveFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Rent-A-Captive Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_RentCaptiveFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Rent Captive Facility [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralAxis" xlink:type="locator" xlink:label="us-gaap_CollateralAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CollateralAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collateral Held</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CollateralAxis" xlink:to="us-gaap_CollateralAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CollateralAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Collateral [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralDomain" xlink:type="locator" xlink:label="us-gaap_CollateralDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CollateralDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collateral Held</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CollateralDomain" xlink:to="us-gaap_CollateralDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CollateralDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Collateral [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralPledgedMember" xlink:type="locator" xlink:label="us-gaap_CollateralPledgedMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CollateralPledgedMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collateral [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CollateralPledgedMember" xlink:to="us-gaap_CollateralPledgedMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CollateralPledgedMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Collateral Pledged [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_SecurityDepositMember" xlink:type="locator" xlink:label="ajg_SecurityDepositMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_SecurityDepositMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Security Deposit [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_SecurityDepositMember" xlink:to="ajg_SecurityDepositMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_SecurityDepositMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Security Deposit [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_SecurityDepositMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Security Deposit [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_ErrorsAndOmissionsMember" xlink:type="locator" xlink:label="ajg_ErrorsAndOmissionsMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_ErrorsAndOmissionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Errors and Omissions [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_ErrorsAndOmissionsMember" xlink:to="ajg_ErrorsAndOmissionsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_ErrorsAndOmissionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Errors And Omissions [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_ErrorsAndOmissionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Errors And Omissions [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCommitmentsAxis" xlink:type="locator" xlink:label="us-gaap_OtherCommitmentsAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherCommitmentsAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Commitments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCommitmentsAxis" xlink:to="us-gaap_OtherCommitmentsAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherCommitmentsAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Commitments [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCommitmentsDomain" xlink:type="locator" xlink:label="us-gaap_OtherCommitmentsDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherCommitmentsDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Commitments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCommitmentsDomain" xlink:to="us-gaap_OtherCommitmentsDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherCommitmentsDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Commitments [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UpToFourPointFiveMillionMember" xlink:type="locator" xlink:label="ajg_UpToFourPointFiveMillionMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_UpToFourPointFiveMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Up to four point five million.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UpToFourPointFiveMillionMember" xlink:to="ajg_UpToFourPointFiveMillionMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_UpToFourPointFiveMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Up to $4.5 Million [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UpToFourPointFiveMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Up To Four Point Five Million [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UpToTenMillionMember" xlink:type="locator" xlink:label="ajg_UpToTenMillionMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_UpToTenMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Up to ten million.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UpToTenMillionMember" xlink:to="ajg_UpToTenMillionMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_UpToTenMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Up to $10 Million [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UpToTenMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Up To Ten Million [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UpToTwentyPointZeroMillionMember" xlink:type="locator" xlink:label="ajg_UpToTwentyPointZeroMillionMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_UpToTwentyPointZeroMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Up to twenty point zero million.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UpToTwentyPointZeroMillionMember" xlink:to="ajg_UpToTwentyPointZeroMillionMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_UpToTwentyPointZeroMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Up to $20.0 Million [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UpToTwentyPointZeroMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Up To Twenty Point Zero Million [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_UpToTwentySevenPointZeroMillionMember" xlink:type="locator" xlink:label="ajg_UpToTwentySevenPointZeroMillionMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_UpToTwentySevenPointZeroMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Up to twenty seven point zero million.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_UpToTwentySevenPointZeroMillionMember" xlink:to="ajg_UpToTwentySevenPointZeroMillionMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_UpToTwentySevenPointZeroMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Up to $27.0 Million [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_UpToTwentySevenPointZeroMillionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Up To Twenty Seven Point Zero Million [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveVerboseLabel">Percentage of equity interests acquired</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfSquareFeet" xlink:type="locator" xlink:label="ajg_NumberOfSquareFeet" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfSquareFeet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of square feet.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfSquareFeet" xlink:to="ajg_NumberOfSquareFeet_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfEmployees" xlink:type="locator" xlink:label="ajg_NumberOfEmployees" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfEmployees_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of employees.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfEmployees" xlink:to="ajg_NumberOfEmployees_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PropertyTaxCreditExpectToReceive" xlink:type="locator" xlink:label="ajg_PropertyTaxCreditExpectToReceive" />
    <link:label xml:lang="en-US" xlink:label="ajg_PropertyTaxCreditExpectToReceive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Property tax credit expect to receive.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PropertyTaxCreditExpectToReceive" xlink:to="ajg_PropertyTaxCreditExpectToReceive_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_EconomicDevelopmentForGrowingEconomyTaxCredit" xlink:type="locator" xlink:label="ajg_EconomicDevelopmentForGrowingEconomyTaxCredit" />
    <link:label xml:lang="en-US" xlink:label="ajg_EconomicDevelopmentForGrowingEconomyTaxCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Economic Development For Growing Economy Tax Credit</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_EconomicDevelopmentForGrowingEconomyTaxCredit" xlink:to="ajg_EconomicDevelopmentForGrowingEconomyTaxCredit_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_PropertyTaxCreditsReceivablePeriod" xlink:type="locator" xlink:label="ajg_PropertyTaxCreditsReceivablePeriod" />
    <link:label xml:lang="en-US" xlink:label="ajg_PropertyTaxCreditsReceivablePeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Property tax credits receivable period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_PropertyTaxCreditsReceivablePeriod" xlink:to="ajg_PropertyTaxCreditsReceivablePeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfSquareFeet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of square feet</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfSquareFeet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Square Feet</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfEmployees_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of employees will accommodate at new facility</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfEmployees_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Employees</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PropertyTaxCreditExpectToReceive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property tax credit expect to receive</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PropertyTaxCreditExpectToReceive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Tax Credit Expect To Receive</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PropertyTaxCreditsReceivablePeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property tax credits receivable period</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_PropertyTaxCreditsReceivablePeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Tax Credits Receivable Period</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EconomicDevelopmentForGrowingEconomyTaxCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Economic development for growing economy tax credit</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EconomicDevelopmentForGrowingEconomyTaxCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Economic Development For Growing Economy Tax Credit</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeasesRentExpenseNet" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesRentExpenseNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeasesRentExpenseNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total rent expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesRentExpenseNet" xlink:to="us-gaap_OperatingLeasesRentExpenseNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeasesRentExpenseNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Leases Rent Expense Net</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearOne" xlink:type="locator" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearOne" />
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of Commitment Expiration Off-Balance Sheet Commitments Within Year One</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearOne" xlink:to="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearOne_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearTwo" xlink:type="locator" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearTwo" />
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of Commitment Expiration Off-Balance Sheet Commitments Within Year Two</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearTwo" xlink:to="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearTwo_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThree" xlink:type="locator" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThree" />
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of Commitment Expiration Off-Balance Sheet Commitments Within Year Three</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThree" xlink:to="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThree_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFour" xlink:type="locator" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFour" />
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of Commitment Expiration Off-Balance Sheet Commitments Within Year Four</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFour" xlink:to="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFour_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFive" xlink:type="locator" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFive" />
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of Commitment Expiration Off-Balance Sheet Commitments Within Year Five</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFive" xlink:to="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFive_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThereafter" xlink:type="locator" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThereafter" />
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThereafter_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of Commitment Expiration Off-Balance Sheet Commitments Within Year Thereafter</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThereafter" xlink:to="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThereafter_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitments" xlink:type="locator" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitments" />
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of Commitment Expiration Off-Balance Sheet Commitments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitments" xlink:to="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitments_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis" xlink:type="locator" xlink:label="us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Category of Item Purchased</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis" xlink:to="us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Purchase Commitment By Category Of Item Purchased [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain" xlink:type="locator" xlink:label="us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term Purchase Commitment, Category of Item Purchased</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain" xlink:to="us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Purchase Commitment Category Of Item Purchased [Domain]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_LettersOfCreditMember" xlink:type="locator" xlink:label="ajg_LettersOfCreditMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_LettersOfCreditMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Letters Of Credit [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_LettersOfCreditMember" xlink:to="ajg_LettersOfCreditMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_LettersOfCreditMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Letters of Credit [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_LettersOfCreditMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Letters Of Credit [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GuaranteeObligationsByNatureAxis" xlink:type="locator" xlink:label="us-gaap_GuaranteeObligationsByNatureAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GuaranteeObligationsByNatureAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Guarantor Obligations, Nature</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GuaranteeObligationsByNatureAxis" xlink:to="us-gaap_GuaranteeObligationsByNatureAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GuaranteeObligationsByNatureAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Guarantee Obligations By Nature [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GuaranteeObligationsNatureDomain" xlink:type="locator" xlink:label="us-gaap_GuaranteeObligationsNatureDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GuaranteeObligationsNatureDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Guarantor Obligations, Nature</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GuaranteeObligationsNatureDomain" xlink:to="us-gaap_GuaranteeObligationsNatureDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GuaranteeObligationsNatureDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Guarantee Obligations Nature [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancialGuaranteeMember" xlink:type="locator" xlink:label="us-gaap_FinancialGuaranteeMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinancialGuaranteeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financial Guarantees [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinancialGuaranteeMember" xlink:to="us-gaap_FinancialGuaranteeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinancialGuaranteeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Financial Guarantee [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amount of Commitment Expiration by Period - 2021</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Amount Of Commitment Expiration Off Balance Sheet Commitments Within Year One</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amount of Commitment Expiration by Period - 2022</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Amount Of Commitment Expiration Off Balance Sheet Commitments Within Year Two</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amount of Commitment Expiration by Period - 2023</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Amount Of Commitment Expiration Off Balance Sheet Commitments Within Year Three</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amount of Commitment Expiration by Period - 2024</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Amount Of Commitment Expiration Off Balance Sheet Commitments Within Year Four</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amount of Commitment Expiration by Period - 2025</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Amount Of Commitment Expiration Off Balance Sheet Commitments Within Year Five</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThereafter_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amount of Commitment Expiration by Period - Thereafter</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitmentsWithinYearThereafter_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Amount Of Commitment Expiration Off Balance Sheet Commitments Within Year Thereafter</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total Amounts Committed</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_AmountOfCommitmentExpirationOffBalanceSheetCommitments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Amount Of Commitment Expiration Off Balance Sheet Commitments</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveVerboseLabel">Ownership interest</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_NumberOfLetterOfCreditIssued" xlink:type="locator" xlink:label="ajg_NumberOfLetterOfCreditIssued" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfLetterOfCreditIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number Of Letter Of Credit Issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_NumberOfLetterOfCreditIssued" xlink:to="ajg_NumberOfLetterOfCreditIssued_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_LiabilitiesRecordedOnSelfInsurance" xlink:type="locator" xlink:label="ajg_LiabilitiesRecordedOnSelfInsurance" />
    <link:label xml:lang="en-US" xlink:label="ajg_LiabilitiesRecordedOnSelfInsurance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Liabilities Recorded on Self-Insurance</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_LiabilitiesRecordedOnSelfInsurance" xlink:to="ajg_LiabilitiesRecordedOnSelfInsurance_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfLetterOfCreditIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of letters of credit issued</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_NumberOfLetterOfCreditIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Letter Of Credit Issued</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveLabel">Debt</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_LiabilitiesRecordedOnSelfInsurance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liabilities recorded on self-insurance</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_LiabilitiesRecordedOnSelfInsurance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities Recorded On Self Insurance</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_Collateral" xlink:type="locator" xlink:label="ajg_Collateral" />
    <link:label xml:lang="en-US" xlink:label="ajg_Collateral_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Collateral</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_Collateral" xlink:to="ajg_Collateral_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CompensationForCommitments" xlink:type="locator" xlink:label="ajg_CompensationForCommitments" />
    <link:label xml:lang="en-US" xlink:label="ajg_CompensationForCommitments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Compensation for commitments.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CompensationForCommitments" xlink:to="ajg_CompensationForCommitments_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CreditSupportUnderLettersOfCreditForDeductiblesDueByUsOnOurOwnInsuranceCoverageExpiresAfterTwoThousandAndTwentyFiveMember" xlink:type="locator" xlink:label="ajg_CreditSupportUnderLettersOfCreditForDeductiblesDueByUsOnOurOwnInsuranceCoverageExpiresAfterTwoThousandAndTwentyFiveMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditSupportUnderLettersOfCreditForDeductiblesDueByUsOnOurOwnInsuranceCoverageExpiresAfterTwoThousandAndTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Credit support under letters of credit for deductibles due by us on our own insurance coverage expires after two thousand and twenty five.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CreditSupportUnderLettersOfCreditForDeductiblesDueByUsOnOurOwnInsuranceCoverageExpiresAfterTwoThousandAndTwentyFiveMember" xlink:to="ajg_CreditSupportUnderLettersOfCreditForDeductiblesDueByUsOnOurOwnInsuranceCoverageExpiresAfterTwoThousandAndTwentyFiveMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditSupportUnderLettersOfCreditForDeductiblesDueByUsOnOurOwnInsuranceCoverageExpiresAfterTwoThousandAndTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Support Under Letters of Credit for Deductibles Due by Us on Our Own Insurance Coverage&apos;s Expires After 2025 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CreditSupportUnderLettersOfCreditForDeductiblesDueByUsOnOurOwnInsuranceCoverageExpiresAfterTwoThousandAndTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Credit Support Under Letters Of Credit For Deductibles Due By Us On Our Own Insurance Coverage Expires After Two Thousand And Twenty Five [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CreditEnhancementUnderLettersOfCreditForOurCaptiveInsuranceOperationsToMeetMinimumStatutoryCapitalRequirementsExpiresAfterTwoThousandAndTwentyFiveMember" xlink:type="locator" xlink:label="ajg_CreditEnhancementUnderLettersOfCreditForOurCaptiveInsuranceOperationsToMeetMinimumStatutoryCapitalRequirementsExpiresAfterTwoThousandAndTwentyFiveMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditEnhancementUnderLettersOfCreditForOurCaptiveInsuranceOperationsToMeetMinimumStatutoryCapitalRequirementsExpiresAfterTwoThousandAndTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Credit enhancement under letters of credit for our captive insurance operations to meet minimum statutory capital requirements expires after two thousand and twenty five.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CreditEnhancementUnderLettersOfCreditForOurCaptiveInsuranceOperationsToMeetMinimumStatutoryCapitalRequirementsExpiresAfterTwoThousandAndTwentyFiveMember" xlink:to="ajg_CreditEnhancementUnderLettersOfCreditForOurCaptiveInsuranceOperationsToMeetMinimumStatutoryCapitalRequirementsExpiresAfterTwoThousandAndTwentyFiveMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditEnhancementUnderLettersOfCreditForOurCaptiveInsuranceOperationsToMeetMinimumStatutoryCapitalRequirementsExpiresAfterTwoThousandAndTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Enhancement Under Letters of Credit for Our Captive Insurance Operations to Meet Minimum Statutory Capital Requirement&apos;s Expires After 2025 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CreditEnhancementUnderLettersOfCreditForOurCaptiveInsuranceOperationsToMeetMinimumStatutoryCapitalRequirementsExpiresAfterTwoThousandAndTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Credit Enhancement Under Letters Of Credit For Our Captive Insurance Operations To Meet Minimum Statutory Capital Requirements Expires After Two Thousand And Twenty Five [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CollateralToClaimFundsHeldInFiduciaryCapacityByRecentAcquisitionExpiresTwoThousandTwentyOneMember" xlink:type="locator" xlink:label="ajg_CollateralToClaimFundsHeldInFiduciaryCapacityByRecentAcquisitionExpiresTwoThousandTwentyOneMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CollateralToClaimFundsHeldInFiduciaryCapacityByRecentAcquisitionExpiresTwoThousandTwentyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Collateral to claim funds held in fiduciary capacity by recent acquisition expires two thousand twenty one.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CollateralToClaimFundsHeldInFiduciaryCapacityByRecentAcquisitionExpiresTwoThousandTwentyOneMember" xlink:to="ajg_CollateralToClaimFundsHeldInFiduciaryCapacityByRecentAcquisitionExpiresTwoThousandTwentyOneMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CollateralToClaimFundsHeldInFiduciaryCapacityByRecentAcquisitionExpiresTwoThousandTwentyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collateral Related to Claims Funds Held in a Fiduciary Capacity by a Recent Acquisition Expires 2021 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CollateralToClaimFundsHeldInFiduciaryCapacityByRecentAcquisitionExpiresTwoThousandTwentyOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Collateral To Claim Funds Held In Fiduciary Capacity By Recent Acquisition Expires Two Thousand Twenty One [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_CreditSupportUnderLettersOfCreditInLieuOfSecurityDepositForAcquisitionLeaseExpiresTwoThousandAndTwentyFiveMember" xlink:type="locator" xlink:label="ajg_CreditSupportUnderLettersOfCreditInLieuOfSecurityDepositForAcquisitionLeaseExpiresTwoThousandAndTwentyFiveMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditSupportUnderLettersOfCreditInLieuOfSecurityDepositForAcquisitionLeaseExpiresTwoThousandAndTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Credit support under letters of credit in lieu of security deposit for acquisition lease expires two thousand and twenty five.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_CreditSupportUnderLettersOfCreditInLieuOfSecurityDepositForAcquisitionLeaseExpiresTwoThousandAndTwentyFiveMember" xlink:to="ajg_CreditSupportUnderLettersOfCreditInLieuOfSecurityDepositForAcquisitionLeaseExpiresTwoThousandAndTwentyFiveMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_CreditSupportUnderLettersOfCreditInLieuOfSecurityDepositForAcquisitionLeaseExpiresTwoThousandAndTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Support Under Letters of Credit in Lieu of Security Deposit for Acquisition Lease Expires 2025 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CreditSupportUnderLettersOfCreditInLieuOfSecurityDepositForAcquisitionLeaseExpiresTwoThousandAndTwentyFiveMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Credit Support Under Letters Of Credit In Lieu Of Security Deposit For Acquisition Lease Expires Two Thousand And Twenty Five [Member]</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_FinancialGuaranteesOfLoansToFiveCanadianBasedEmployeesTriggerMember" xlink:type="locator" xlink:label="ajg_FinancialGuaranteesOfLoansToFiveCanadianBasedEmployeesTriggerMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_FinancialGuaranteesOfLoansToFiveCanadianBasedEmployeesTriggerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Financial guarantees of loans to five Canadian based employees trigger.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_FinancialGuaranteesOfLoansToFiveCanadianBasedEmployeesTriggerMember" xlink:to="ajg_FinancialGuaranteesOfLoansToFiveCanadianBasedEmployeesTriggerMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_FinancialGuaranteesOfLoansToFiveCanadianBasedEmployeesTriggerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financial Guarantees of Loans to Five Canadian Based Employees Trigger [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_FinancialGuaranteesOfLoansToFiveCanadianBasedEmployeesTriggerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Financial Guarantees Of Loans To Five Canadian Based Employees Trigger [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_Collateral_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collateral</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_Collateral_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Collateral</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CompensationForCommitments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Compensation to Us</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_CompensationForCommitments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Compensation For Commitments</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Maximum Exposure</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_LiabilitiesRecordedOnSelfInsurance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Liability Recorded</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_MicroCaptiveInsuranceCompaniesManaged" xlink:type="locator" xlink:label="ajg_MicroCaptiveInsuranceCompaniesManaged" />
    <link:label xml:lang="en-US" xlink:label="ajg_MicroCaptiveInsuranceCompaniesManaged_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Micro captive Insurance Companies Managed</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_MicroCaptiveInsuranceCompaniesManaged" xlink:to="ajg_MicroCaptiveInsuranceCompaniesManaged_lbl" />
    <link:label xml:lang="en-US" xlink:label="ajg_MicroCaptiveInsuranceCompaniesManaged_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of micro-captive insurance companies organized or managed</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_MicroCaptiveInsuranceCompaniesManaged_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Micro Captive Insurance Companies Managed</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense" xlink:type="locator" xlink:label="us-gaap_SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Insurance claims, amount retained</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense" xlink:to="us-gaap_SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Supplementary Insurance Information Benefits Claims Losses And Settlement Expense</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SupplementaryInsuranceInformationOtherPolicyClaimsAndBenefitsPayable" xlink:type="locator" xlink:label="us-gaap_SupplementaryInsuranceInformationOtherPolicyClaimsAndBenefitsPayable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SupplementaryInsuranceInformationOtherPolicyClaimsAndBenefitsPayable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Insurance claim arise during ordinary course of business</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementaryInsuranceInformationOtherPolicyClaimsAndBenefitsPayable" xlink:to="us-gaap_SupplementaryInsuranceInformationOtherPolicyClaimsAndBenefitsPayable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SupplementaryInsuranceInformationOtherPolicyClaimsAndBenefitsPayable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Supplementary Insurance Information Other Policy Claims And Benefits Payable</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductLiabilityContingencyAccrualPresentValue" xlink:type="locator" xlink:label="us-gaap_ProductLiabilityContingencyAccrualPresentValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProductLiabilityContingencyAccrualPresentValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Actuarial range value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductLiabilityContingencyAccrualPresentValue" xlink:to="us-gaap_ProductLiabilityContingencyAccrualPresentValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProductLiabilityContingencyAccrualPresentValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Product Liability Contingency Accrual Present Value</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxCreditsAndAdjustments" xlink:type="locator" xlink:label="us-gaap_IncomeTaxCreditsAndAdjustments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxCreditsAndAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income tax credits and adjustments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxCreditsAndAdjustments" xlink:to="us-gaap_IncomeTaxCreditsAndAdjustments_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxCreditsAndAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Credits And Adjustments</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PremiumsWrittenAndEarnedAbstract" xlink:type="locator" xlink:label="us-gaap_PremiumsWrittenAndEarnedAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PremiumsWrittenAndEarnedAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Premiums Written And Earned [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PremiumsWrittenAndEarnedAbstract" xlink:to="us-gaap_PremiumsWrittenAndEarnedAbstract_lbl" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DirectPremiumsWritten" xlink:type="locator" xlink:label="us-gaap_DirectPremiumsWritten" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DirectPremiumsWritten_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Written, Direct</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DirectPremiumsWritten" xlink:to="us-gaap_DirectPremiumsWritten_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DirectPremiumsWritten_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Direct Premiums Written</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssumedPremiumsWritten" xlink:type="locator" xlink:label="us-gaap_AssumedPremiumsWritten" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssumedPremiumsWritten_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Written, Assumed</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssumedPremiumsWritten" xlink:to="us-gaap_AssumedPremiumsWritten_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssumedPremiumsWritten_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Assumed Premiums Written</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CededPremiumsWritten" xlink:type="locator" xlink:label="us-gaap_CededPremiumsWritten" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CededPremiumsWritten_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Written, Ceded</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CededPremiumsWritten" xlink:to="us-gaap_CededPremiumsWritten_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CededPremiumsWritten_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Ceded Premiums Written</link:label>
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_IncomeTaxExpenseBenefitLineItems" xlink:type="locator" xlink:label="ajg_IncomeTaxExpenseBenefitLineItems" />
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_IncomeTaxExpenseBenefitTable" xlink:type="locator" xlink:label="ajg_IncomeTaxExpenseBenefitTable" />
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_NoncurrentLiabilitiesMember" xlink:type="locator" xlink:label="ajg_NoncurrentLiabilitiesMember" />
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    <link:label xml:lang="en-US" xlink:label="ajg_NoncurrentLiabilitiesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Noncurrent Liabilities [Member]</link:label>
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_GeneralBusinessAndOtherMember" xlink:type="locator" xlink:label="ajg_GeneralBusinessAndOtherMember" />
    <link:label xml:lang="en-US" xlink:label="ajg_GeneralBusinessAndOtherMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">General business and other.</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:type="locator" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential" xlink:type="locator" xlink:label="us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationTaxCredits" xlink:type="locator" xlink:label="us-gaap_IncomeTaxReconciliationTaxCredits" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:type="locator" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" />
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_IncreaseDecreaseInEffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings" xlink:type="locator" xlink:label="ajg_IncreaseDecreaseInEffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings" />
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    <link:label xml:lang="en-US" xlink:label="ajg_IncreaseDecreaseInEffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. repatriation tax</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost</link:label>
    <link:label xml:lang="en-US" xlink:label="ajg_EffectiveIncomeTaxRateReconciliationChangesInUnrecognizedTaxBenefitsRelatedToResolutionOfFederalAndStateAuditsExpirationOfVariousStatutesOfLimitationsAndOtherItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Changes in unrecognized tax benefits, % of Pretax Earnings</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in valuation allowance, % of Pretax Earnings</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in U.S. and U.K. tax rates</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other, % of Pretax Earnings</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Other Adjustments</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total provision (benefit) for income taxes, % of Pretax Earnings</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Continuing Operations</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:type="locator" xlink:label="us-gaap_UnrecognizedTaxBenefits" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Gross unrecognized tax benefits at January</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefits" xlink:to="us-gaap_UnrecognizedTaxBenefits_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:type="locator" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Increases in tax positions for current year</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities" xlink:type="locator" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Settlements</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities" xlink:to="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" xlink:type="locator" xlink:label="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Lapse in statute of limitations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" xlink:to="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:type="locator" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Increases in tax positions for prior years</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:type="locator" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Decreases in tax positions for prior years</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:to="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Gross unrecognized tax benefits at December</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:type="locator" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net unrecognized tax benefits</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:to="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits That Would Impact Effective Tax Rate</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:type="locator" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued interest and penalties related to unrecognized tax benefits</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OpenTaxYear" xlink:type="locator" xlink:label="us-gaap_OpenTaxYear" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OpenTaxYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Open tax year</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_OpenTaxYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Open Tax Year</link:label>
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredTaxAssetsAlternativeMinimumTaxAndOtherCreditCarryforwards" xlink:type="locator" xlink:label="ajg_DeferredTaxAssetsAlternativeMinimumTaxAndOtherCreditCarryforwards" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredTaxAssetsAlternativeMinimumTaxAndOtherCreditCarryforwards_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Tax Assets, Alternative minimum tax and other credit carryforwards.</link:label>
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredTaxAssetsAccruedAndUnfundedCompensationAndEmployeeBenefits" xlink:type="locator" xlink:label="ajg_DeferredTaxAssetsAccruedAndUnfundedCompensationAndEmployeeBenefits" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredTaxAssetsAccruedAndUnfundedCompensationAndEmployeeBenefits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Tax Assets, Accrued and unfunded compensation and employee benefits.</link:label>
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredTaxAssetsAccruedPensionLiability" xlink:type="locator" xlink:label="ajg_DeferredTaxAssetsAccruedPensionLiability" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredTaxAssetsAccruedPensionLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax assets, accrued pension liability</link:label>
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    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredTaxAssetsLeaseLiabilities" xlink:type="locator" xlink:label="ajg_DeferredTaxAssetsLeaseLiabilities" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredTaxAssetsLeaseLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax assets lease liabilities.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DeferredTaxAssetsLeaseLiabilities" xlink:to="ajg_DeferredTaxAssetsLeaseLiabilities_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredTaxLiabilitiesInvestmentRelatedPartnerships" xlink:type="locator" xlink:label="ajg_DeferredTaxLiabilitiesInvestmentRelatedPartnerships" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredTaxLiabilitiesInvestmentRelatedPartnerships_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax liabilities, investment-related partnerships</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DeferredTaxLiabilitiesInvestmentRelatedPartnerships" xlink:to="ajg_DeferredTaxLiabilitiesInvestmentRelatedPartnerships_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredTaxLiabilitiesDepreciableFixedAssets" xlink:type="locator" xlink:label="ajg_DeferredTaxLiabilitiesDepreciableFixedAssets" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredTaxLiabilitiesDepreciableFixedAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax liabilities, depreciable fixed assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DeferredTaxLiabilitiesDepreciableFixedAssets" xlink:to="ajg_DeferredTaxLiabilitiesDepreciableFixedAssets_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredTaxLiabilitiesRightOfUseAsset" xlink:type="locator" xlink:label="ajg_DeferredTaxLiabilitiesRightOfUseAsset" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredTaxLiabilitiesRightOfUseAsset_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax liabilities right of use asset</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DeferredTaxLiabilitiesRightOfUseAsset" xlink:to="ajg_DeferredTaxLiabilitiesRightOfUseAsset_lbl" />
    <link:loc xlink:href="ajg-20201231.xsd#ajg_DeferredTaxLiabilitiesRevenueRecognition" xlink:type="locator" xlink:label="ajg_DeferredTaxLiabilitiesRevenueRecognition" />
    <link:label xml:lang="en-US" xlink:label="ajg_DeferredTaxLiabilitiesRevenueRecognition_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Tax Liabilities Revenue Recognition</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ajg_DeferredTaxLiabilitiesRevenueRecognition" xlink:to="ajg_DeferredTaxLiabilitiesRevenueRecognition_lbl" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsInvestments" xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsInvestments" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsCapitalLossCarryforwards" xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsCapitalLossCarryforwards" />
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    <link:label xml:lang="en-US" xlink:label="ajg_DeferredTaxAssetsLeaseLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lease liabilities</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsHedgingTransactions" xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsHedgingTransactions" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsOther" xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsOther" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsGross" xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsGross" />
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