<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019c9aa7-360b-72aa-a730-4fbf51b80e40,g:d8f5efc1-5a7a-4dad-83b8-0f61a97458c8-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.grainger.com/role/CONDENSEDCONSOLIDATEDSTATEMENTOFSHAREDHOLDERSEQUITY" xlink:type="simple" xlink:href="gww-20260331.xsd#CONDENSEDCONSOLIDATEDSTATEMENTOFSHAREDHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://www.grainger.com/role/CONDENSEDCONSOLIDATEDSTATEMENTOFSHAREDHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019c9aa7-378b-730e-a849-b8733f68e40c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019c9aa7-378b-71d9-9fd1-9e972030c04d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019c9aa7-378b-730e-a849-b8733f68e40c" xlink:to="loc_us-gaap_StatementTable_019c9aa7-378b-71d9-9fd1-9e972030c04d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019c9aa7-378b-722d-a260-dc2806200b07" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019c9aa7-378b-71d9-9fd1-9e972030c04d" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019c9aa7-378b-722d-a260-dc2806200b07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019c9aa7-378b-722d-a260-dc2806200b07_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019c9aa7-378b-722d-a260-dc2806200b07" xlink:to="loc_us-gaap_EquityComponentDomain_019c9aa7-378b-722d-a260-dc2806200b07_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019c9aa7-378b-7ff9-bbdb-1f0fdb0a27e2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019c9aa7-378b-722d-a260-dc2806200b07" xlink:to="loc_us-gaap_EquityComponentDomain_019c9aa7-378b-7ff9-bbdb-1f0fdb0a27e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019c9aa7-378b-7df1-bb7d-8a07d9df2610" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019c9aa7-378b-7ff9-bbdb-1f0fdb0a27e2" xlink:to="loc_us-gaap_CommonStockMember_019c9aa7-378b-7df1-bb7d-8a07d9df2610" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019c9aa7-378b-7884-b7cf-c851ec2bc593" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019c9aa7-378b-7ff9-bbdb-1f0fdb0a27e2" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019c9aa7-378b-7884-b7cf-c851ec2bc593" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019c9aa7-378b-70be-8488-0ebeb6c2f46e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019c9aa7-378b-7ff9-bbdb-1f0fdb0a27e2" xlink:to="loc_us-gaap_RetainedEarningsMember_019c9aa7-378b-70be-8488-0ebeb6c2f46e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019c9aa7-378b-7abb-a958-033bedcd08fa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019c9aa7-378b-7ff9-bbdb-1f0fdb0a27e2" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019c9aa7-378b-7abb-a958-033bedcd08fa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_019c9aa7-378b-7b79-9173-4cbe5ad02787" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019c9aa7-378b-7ff9-bbdb-1f0fdb0a27e2" xlink:to="loc_us-gaap_TreasuryStockCommonMember_019c9aa7-378b-7b79-9173-4cbe5ad02787" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_019c9aa7-378b-7ece-bb5c-05980b9d4797" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019c9aa7-378b-7ff9-bbdb-1f0fdb0a27e2" xlink:to="loc_us-gaap_NoncontrollingInterestMember_019c9aa7-378b-7ece-bb5c-05980b9d4797" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c9aa7-378b-7d2c-a91f-77a0d3f03b2f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019c9aa7-378b-730e-a849-b8733f68e40c" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c9aa7-378b-7d2c-a91f-77a0d3f03b2f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019c9aa7-378b-74aa-9fe5-d07b3a55d055" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c9aa7-378b-7d2c-a91f-77a0d3f03b2f" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019c9aa7-378b-74aa-9fe5-d07b3a55d055" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition_019c9aa7-378b-7319-a51d-9199b8f60e4d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c9aa7-378b-7d2c-a91f-77a0d3f03b2f" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition_019c9aa7-378b-7319-a51d-9199b8f60e4d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_019c9aa7-378b-76a1-82a0-d00f697f6fd0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c9aa7-378b-7d2c-a91f-77a0d3f03b2f" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_019c9aa7-378b-76a1-82a0-d00f697f6fd0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_019dab10-bc25-7378-b90c-b34b3def2cfe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MinorityInterestDecreaseFromRedemptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c9aa7-378b-7d2c-a91f-77a0d3f03b2f" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_019dab10-bc25-7378-b90c-b34b3def2cfe" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019c9aa7-378b-714b-8a16-ad069e1db92b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c9aa7-378b-7d2c-a91f-77a0d3f03b2f" xlink:to="loc_us-gaap_ProfitLoss_019c9aa7-378b-714b-8a16-ad069e1db92b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019c9aa7-378b-7567-8039-fd73d68bb7c8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c9aa7-378b-7d2c-a91f-77a0d3f03b2f" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019c9aa7-378b-7567-8039-fd73d68bb7c8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStockCash_019c9aa7-378b-7a0a-aafa-6759bc9ba008" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsCommonStockCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019c9aa7-378b-7d2c-a91f-77a0d3f03b2f" xlink:to="loc_us-gaap_DividendsCommonStockCash_019c9aa7-378b-7a0a-aafa-6759bc9ba008" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019c9aa7-378b-7b95-bc61-3f8946c11874" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.grainger.com/role/REVENUEDisaggregationofRevenuesDetails" xlink:type="simple" xlink:href="gww-20260331.xsd#REVENUEDisaggregationofRevenuesDetails"/>
  <link:definitionLink xlink:role="http://www.grainger.com/role/REVENUEDisaggregationofRevenuesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019c9aa7-378b-7df0-bc1a-893fe7abfba6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019c9aa7-378b-794b-923d-38fe0e5f03a1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019c9aa7-378b-7df0-bc1a-893fe7abfba6" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019c9aa7-378b-794b-923d-38fe0e5f03a1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378b-762e-ae3a-9d2a815417f3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019c9aa7-378b-794b-923d-38fe0e5f03a1" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378b-762e-ae3a-9d2a815417f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019c9aa7-378b-762e-ae3a-9d2a815417f3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378b-762e-ae3a-9d2a815417f3" xlink:to="loc_us-gaap_SegmentDomain_019c9aa7-378b-762e-ae3a-9d2a815417f3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019c9aa7-378b-7a0e-a690-8d84bd13d5f8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378b-762e-ae3a-9d2a815417f3" xlink:to="loc_us-gaap_SegmentDomain_019c9aa7-378b-7a0e-a690-8d84bd13d5f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_HighTouchSolutionsNAMember_019c9aa7-378b-7a14-b44e-fb0f37327987" xlink:href="gww-20260331.xsd#gww_HighTouchSolutionsNAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019c9aa7-378b-7a0e-a690-8d84bd13d5f8" xlink:to="loc_gww_HighTouchSolutionsNAMember_019c9aa7-378b-7a14-b44e-fb0f37327987" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_EndlessAssortmentMember_019c9aa7-378b-7b9a-82a4-8aef2be46ec5" xlink:href="gww-20260331.xsd#gww_EndlessAssortmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019c9aa7-378b-7a0e-a690-8d84bd13d5f8" xlink:to="loc_gww_EndlessAssortmentMember_019c9aa7-378b-7b9a-82a4-8aef2be46ec5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_019c9aa7-378b-7669-85d5-1d2c7fcd450e" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019c9aa7-378b-794b-923d-38fe0e5f03a1" xlink:to="loc_srt_MajorCustomersAxis_019c9aa7-378b-7669-85d5-1d2c7fcd450e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7669-85d5-1d2c7fcd450e_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_019c9aa7-378b-7669-85d5-1d2c7fcd450e" xlink:to="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7669-85d5-1d2c7fcd450e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_019c9aa7-378b-7669-85d5-1d2c7fcd450e" xlink:to="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_ManufacturingMember_019c9aa7-378b-7f2d-bc15-88785cf855d3" xlink:href="gww-20260331.xsd#gww_ManufacturingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:to="loc_gww_ManufacturingMember_019c9aa7-378b-7f2d-bc15-88785cf855d3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_GovernmentCustomerMember_019c9aa7-378b-723c-b8ed-6d4b34e2178d" xlink:href="gww-20260331.xsd#gww_GovernmentCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:to="loc_gww_GovernmentCustomerMember_019c9aa7-378b-723c-b8ed-6d4b34e2178d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_WholesaleMember_019c9aa7-378b-7336-8d7b-99462dda411d" xlink:href="gww-20260331.xsd#gww_WholesaleMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:to="loc_gww_WholesaleMember_019c9aa7-378b-7336-8d7b-99462dda411d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_CommercialServicesMember_019c9aa7-378b-7ef9-8712-de4e1ff45755" xlink:href="gww-20260331.xsd#gww_CommercialServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:to="loc_gww_CommercialServicesMember_019c9aa7-378b-7ef9-8712-de4e1ff45755" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_ContractorsMember_019c9aa7-378b-777b-839b-47b864bdb291" xlink:href="gww-20260331.xsd#gww_ContractorsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:to="loc_gww_ContractorsMember_019c9aa7-378b-777b-839b-47b864bdb291" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_HealthcareIndustryMember_019dd075-4b4f-7c0b-91e2-7dd01e9b6ac8" xlink:href="gww-20260331.xsd#gww_HealthcareIndustryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:to="loc_gww_HealthcareIndustryMember_019dd075-4b4f-7c0b-91e2-7dd01e9b6ac8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_RetailCustomerMember_019c9aa7-378b-77be-a68e-ce26d4fb8491" xlink:href="gww-20260331.xsd#gww_RetailCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:to="loc_gww_RetailCustomerMember_019c9aa7-378b-77be-a68e-ce26d4fb8491" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_TransportationMember_019c9aa7-378b-7c45-9b0f-207d32ad944e" xlink:href="gww-20260331.xsd#gww_TransportationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:to="loc_gww_TransportationMember_019c9aa7-378b-7c45-9b0f-207d32ad944e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_UtilitiesMember_019c9aa7-378b-7c6a-a7b2-e1da647422e2" xlink:href="gww-20260331.xsd#gww_UtilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:to="loc_gww_UtilitiesMember_019c9aa7-378b-7c6a-a7b2-e1da647422e2" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_WarehousingMember_019c9aa7-378b-757d-96c7-f0f2ddc03556" xlink:href="gww-20260331.xsd#gww_WarehousingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:to="loc_gww_WarehousingMember_019c9aa7-378b-757d-96c7-f0f2ddc03556" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_OtherMember_019c9aa7-378b-7c7b-83e1-ae89445e5b66" xlink:href="gww-20260331.xsd#gww_OtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019c9aa7-378b-7ef5-acc1-30f328f6e550" xlink:to="loc_gww_OtherMember_019c9aa7-378b-7c7b-83e1-ae89445e5b66" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019dd1b3-0767-7862-ba68-4685dc0d9b93" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019c9aa7-378b-794b-923d-38fe0e5f03a1" xlink:to="loc_srt_ConsolidationItemsAxis_019dd1b3-0767-7862-ba68-4685dc0d9b93" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019dd1b3-0767-7862-ba68-4685dc0d9b93_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019dd1b3-0767-7862-ba68-4685dc0d9b93" xlink:to="loc_srt_ConsolidationItemsDomain_019dd1b3-0767-7862-ba68-4685dc0d9b93_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019dd1b3-0767-7f86-80a2-7854fde1fd8a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019dd1b3-0767-7862-ba68-4685dc0d9b93" xlink:to="loc_srt_ConsolidationItemsDomain_019dd1b3-0767-7f86-80a2-7854fde1fd8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_019dd1b3-3d46-7c3a-aaeb-3abb503014da" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019dd1b3-0767-7f86-80a2-7854fde1fd8a" xlink:to="loc_us-gaap_CorporateNonSegmentMember_019dd1b3-3d46-7c3a-aaeb-3abb503014da" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_RevenueFromContractWithCustomerExcludingAssessedTaxPercentage_019c9aa7-378b-7816-926b-f533e7b2069c" xlink:href="gww-20260331.xsd#gww_RevenueFromContractWithCustomerExcludingAssessedTaxPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019c9aa7-378b-7df0-bc1a-893fe7abfba6" xlink:to="loc_gww_RevenueFromContractWithCustomerExcludingAssessedTaxPercentage_019c9aa7-378b-7816-926b-f533e7b2069c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_RevenueFromContractWithCustomerExcludingAssessedTaxPercentageOfCompanyWideRevenue_019c9aa7-378b-7c26-ae41-65afa78059ae" xlink:href="gww-20260331.xsd#gww_RevenueFromContractWithCustomerExcludingAssessedTaxPercentageOfCompanyWideRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019c9aa7-378b-7df0-bc1a-893fe7abfba6" xlink:to="loc_gww_RevenueFromContractWithCustomerExcludingAssessedTaxPercentageOfCompanyWideRevenue_019c9aa7-378b-7c26-ae41-65afa78059ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_PercentageOfCompanyWideRevenue_019c9aa7-378b-780e-bad7-fc2106684468" xlink:href="gww-20260331.xsd#gww_PercentageOfCompanyWideRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019c9aa7-378b-7df0-bc1a-893fe7abfba6" xlink:to="loc_gww_PercentageOfCompanyWideRevenue_019c9aa7-378b-780e-bad7-fc2106684468" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.grainger.com/role/PROPERTYBUILDINGSANDEQUIPMENTDetails" xlink:type="simple" xlink:href="gww-20260331.xsd#PROPERTYBUILDINGSANDEQUIPMENTDetails"/>
  <link:definitionLink xlink:role="http://www.grainger.com/role/PROPERTYBUILDINGSANDEQUIPMENTDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019c9aa7-378b-7f5f-8780-3728492d83a0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019c9aa7-378b-7144-a477-644e4433a865" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019c9aa7-378b-7f5f-8780-3728492d83a0" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019c9aa7-378b-7144-a477-644e4433a865" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019c9aa7-378b-7b62-bb6a-d831d7671723" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019c9aa7-378b-7144-a477-644e4433a865" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019c9aa7-378b-7b62-bb6a-d831d7671723" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019c9aa7-378b-7b62-bb6a-d831d7671723_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019c9aa7-378b-7b62-bb6a-d831d7671723" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019c9aa7-378b-7b62-bb6a-d831d7671723_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019c9aa7-378b-746c-9830-9da63634a54d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019c9aa7-378b-7b62-bb6a-d831d7671723" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019c9aa7-378b-746c-9830-9da63634a54d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandMember_019c9aa7-378b-754d-99bb-e24b295ec425" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019c9aa7-378b-746c-9830-9da63634a54d" xlink:to="loc_us-gaap_LandMember_019c9aa7-378b-754d-99bb-e24b295ec425" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember_019c9aa7-378b-79a2-91d7-27e6073425a2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BuildingAndBuildingImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019c9aa7-378b-746c-9830-9da63634a54d" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_019c9aa7-378b-79a2-91d7-27e6073425a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_FurnitureFixturesMachineryandEquipmentMember_019c9aa7-378b-7009-a64a-0bcdff93a860" xlink:href="gww-20260331.xsd#gww_FurnitureFixturesMachineryandEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019c9aa7-378b-746c-9830-9da63634a54d" xlink:to="loc_gww_FurnitureFixturesMachineryandEquipmentMember_019c9aa7-378b-7009-a64a-0bcdff93a860" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019c9aa7-378b-78c7-b9a1-3ea734f7b369" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019c9aa7-378b-7f5f-8780-3728492d83a0" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019c9aa7-378b-78c7-b9a1-3ea734f7b369" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019c9aa7-378b-7e06-b23c-180e876a3438" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019c9aa7-378b-7f5f-8780-3728492d83a0" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019c9aa7-378b-7e06-b23c-180e876a3438" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019c9aa7-378b-77d1-bece-b7d0334169db" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019c9aa7-378b-7f5f-8780-3728492d83a0" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019c9aa7-378b-77d1-bece-b7d0334169db" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.grainger.com/role/GOODWILLANDOTHERINTANGIBLEASSETSBalancesandChangesinCarryingAmountsofGoodwillDetails" xlink:type="simple" xlink:href="gww-20260331.xsd#GOODWILLANDOTHERINTANGIBLEASSETSBalancesandChangesinCarryingAmountsofGoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.grainger.com/role/GOODWILLANDOTHERINTANGIBLEASSETSBalancesandChangesinCarryingAmountsofGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_019c9aa7-378b-714f-9d5f-5a9df4b4148e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_019c9aa7-378b-75fa-bebe-669fd70e03e7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_019c9aa7-378b-714f-9d5f-5a9df4b4148e" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_019c9aa7-378b-75fa-bebe-669fd70e03e7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378b-7aac-8fe2-6e260891ae9e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_019c9aa7-378b-75fa-bebe-669fd70e03e7" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378b-7aac-8fe2-6e260891ae9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019c9aa7-378b-7aac-8fe2-6e260891ae9e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378b-7aac-8fe2-6e260891ae9e" xlink:to="loc_us-gaap_SegmentDomain_019c9aa7-378b-7aac-8fe2-6e260891ae9e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019c9aa7-378b-765f-9bbe-5098b708c148" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378b-7aac-8fe2-6e260891ae9e" xlink:to="loc_us-gaap_SegmentDomain_019c9aa7-378b-765f-9bbe-5098b708c148" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_HighTouchSolutionsNAMember_019c9aa7-378b-79ae-83e0-e80cfb3626e7" xlink:href="gww-20260331.xsd#gww_HighTouchSolutionsNAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019c9aa7-378b-765f-9bbe-5098b708c148" xlink:to="loc_gww_HighTouchSolutionsNAMember_019c9aa7-378b-79ae-83e0-e80cfb3626e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_EndlessAssortmentMember_019c9aa7-378b-7471-9332-eefb21a65380" xlink:href="gww-20260331.xsd#gww_EndlessAssortmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019c9aa7-378b-765f-9bbe-5098b708c148" xlink:to="loc_gww_EndlessAssortmentMember_019c9aa7-378b-7471-9332-eefb21a65380" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019c9aa7-378b-70e8-a060-043658673b30" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_019c9aa7-378b-75fa-bebe-669fd70e03e7" xlink:to="loc_srt_ConsolidationItemsAxis_019c9aa7-378b-70e8-a060-043658673b30" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019c9aa7-378b-70e8-a060-043658673b30_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019c9aa7-378b-70e8-a060-043658673b30" xlink:to="loc_srt_ConsolidationItemsDomain_019c9aa7-378b-70e8-a060-043658673b30_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019c9aa7-378b-74df-b997-0cf4bc8da2d7" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019c9aa7-378b-70e8-a060-043658673b30" xlink:to="loc_srt_ConsolidationItemsDomain_019c9aa7-378b-74df-b997-0cf4bc8da2d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019c9aa7-378b-769d-86db-2f7eb7ea86d7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019c9aa7-378b-74df-b997-0cf4bc8da2d7" xlink:to="loc_us-gaap_OperatingSegmentsMember_019c9aa7-378b-769d-86db-2f7eb7ea86d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_019c9aa7-378b-7180-8d0e-4dfe253ca846" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019c9aa7-378b-714f-9d5f-5a9df4b4148e" xlink:to="loc_us-gaap_GoodwillRollForward_019c9aa7-378b-7180-8d0e-4dfe253ca846" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019c9aa7-378b-7991-a6f8-4579b03afac3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019c9aa7-378b-7180-8d0e-4dfe253ca846" xlink:to="loc_us-gaap_Goodwill_019c9aa7-378b-7991-a6f8-4579b03afac3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_019c9aa7-378b-7281-92fa-42463540d758" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019c9aa7-378b-7180-8d0e-4dfe253ca846" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_019c9aa7-378b-7281-92fa-42463540d758" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019c9aa7-378b-78a7-be9e-3d26104e023c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.grainger.com/role/GOODWILLANDOTHERINTANGIBLEASSETSNarrativeDetails" xlink:type="simple" xlink:href="gww-20260331.xsd#GOODWILLANDOTHERINTANGIBLEASSETSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.grainger.com/role/GOODWILLANDOTHERINTANGIBLEASSETSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019c9aa7-378b-7cfc-94cf-d10da0955035" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019c9aa7-378b-7600-8d87-0a96dc1a651d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019c9aa7-378b-7cfc-94cf-d10da0955035" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019c9aa7-378b-7600-8d87-0a96dc1a651d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019c9aa7-378b-797b-9650-474f102cbbca" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019c9aa7-378b-7600-8d87-0a96dc1a651d" xlink:to="loc_srt_ConsolidationItemsAxis_019c9aa7-378b-797b-9650-474f102cbbca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019c9aa7-378b-797b-9650-474f102cbbca_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019c9aa7-378b-797b-9650-474f102cbbca" xlink:to="loc_srt_ConsolidationItemsDomain_019c9aa7-378b-797b-9650-474f102cbbca_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019c9aa7-378b-768e-95ba-9feab440fb0d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019c9aa7-378b-797b-9650-474f102cbbca" xlink:to="loc_srt_ConsolidationItemsDomain_019c9aa7-378b-768e-95ba-9feab440fb0d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019c9aa7-378b-71f1-9af4-92a10182e2c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019c9aa7-378b-768e-95ba-9feab440fb0d" xlink:to="loc_us-gaap_OperatingSegmentsMember_019c9aa7-378b-71f1-9af4-92a10182e2c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetImpairment_019c9aa7-378b-77e7-9ddb-3f40de61b33d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillAndIntangibleAssetImpairment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019c9aa7-378b-7cfc-94cf-d10da0955035" xlink:to="loc_us-gaap_GoodwillAndIntangibleAssetImpairment_019c9aa7-378b-77e7-9ddb-3f40de61b33d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.grainger.com/role/GOODWILLANDOTHERINTANGIBLEASSETSBalanceinIntangibleAssetsNetDetails" xlink:type="simple" xlink:href="gww-20260331.xsd#GOODWILLANDOTHERINTANGIBLEASSETSBalanceinIntangibleAssetsNetDetails"/>
  <link:definitionLink xlink:role="http://www.grainger.com/role/GOODWILLANDOTHERINTANGIBLEASSETSBalanceinIntangibleAssetsNetDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019c9aa7-378b-7daa-9735-51ed93fa3bed" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019c9aa7-378b-7888-a1fd-d760b2982f3a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019c9aa7-378b-7daa-9735-51ed93fa3bed" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019c9aa7-378b-7888-a1fd-d760b2982f3a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_019c9aa7-378b-719c-8110-0b2499d02a05" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019c9aa7-378b-7888-a1fd-d760b2982f3a" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_019c9aa7-378b-719c-8110-0b2499d02a05" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019c9aa7-378b-719c-8110-0b2499d02a05_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_019c9aa7-378b-719c-8110-0b2499d02a05" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019c9aa7-378b-719c-8110-0b2499d02a05_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019c9aa7-378b-7b43-b6ee-7ec05e534c10" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_019c9aa7-378b-719c-8110-0b2499d02a05" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019c9aa7-378b-7b43-b6ee-7ec05e534c10" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelatedIntangibleAssetsMember_019c9aa7-378b-71b3-a17e-d19c152db91c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerRelatedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019c9aa7-378b-7b43-b6ee-7ec05e534c10" xlink:to="loc_us-gaap_CustomerRelatedIntangibleAssetsMember_019c9aa7-378b-71b3-a17e-d19c152db91c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_019c9aa7-378b-76bf-bb72-cdae8753fcda" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TrademarksAndTradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019c9aa7-378b-7b43-b6ee-7ec05e534c10" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_019c9aa7-378b-76bf-bb72-cdae8753fcda" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefinitelivedIntangibleAssetsMember_019c9aa7-378b-7f5c-85af-a0b1b3fb0d7a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IndefinitelivedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019c9aa7-378b-7b43-b6ee-7ec05e534c10" xlink:to="loc_us-gaap_IndefinitelivedIntangibleAssetsMember_019c9aa7-378b-7f5c-85af-a0b1b3fb0d7a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_019c9aa7-378b-77ed-81ac-edd66ceafbc0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SoftwareAndSoftwareDevelopmentCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019c9aa7-378b-7b43-b6ee-7ec05e534c10" xlink:to="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_019c9aa7-378b-77ed-81ac-edd66ceafbc0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019c9aa7-378b-7726-a0b2-9ae5f3812546" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019c9aa7-378b-7888-a1fd-d760b2982f3a" xlink:to="loc_srt_RangeAxis_019c9aa7-378b-7726-a0b2-9ae5f3812546" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019c9aa7-378b-7726-a0b2-9ae5f3812546_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019c9aa7-378b-7726-a0b2-9ae5f3812546" xlink:to="loc_srt_RangeMember_019c9aa7-378b-7726-a0b2-9ae5f3812546_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019c9aa7-378b-7ea1-abf9-6073a44c5499" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019c9aa7-378b-7726-a0b2-9ae5f3812546" xlink:to="loc_srt_RangeMember_019c9aa7-378b-7ea1-abf9-6073a44c5499" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_WeightedAverageMember_019c9aa7-378b-72c4-8cc8-135a157575ca" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_WeightedAverageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019c9aa7-378b-7ea1-abf9-6073a44c5499" xlink:to="loc_srt_WeightedAverageMember_019c9aa7-378b-72c4-8cc8-135a157575ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_019c9aa7-378b-71c4-8c8a-2713ead24c14" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019c9aa7-378b-7daa-9735-51ed93fa3bed" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_019c9aa7-378b-71c4-8c8a-2713ead24c14" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019c9aa7-378b-728f-8a42-7f0e32447d88" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019c9aa7-378b-7daa-9735-51ed93fa3bed" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019c9aa7-378b-728f-8a42-7f0e32447d88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_019c9aa7-378b-7188-97b0-91eaa06763f5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019c9aa7-378b-7daa-9735-51ed93fa3bed" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_019c9aa7-378b-7188-97b0-91eaa06763f5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019c9aa7-378b-7abc-8aaa-6168f8f8fc32" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019c9aa7-378b-7daa-9735-51ed93fa3bed" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019c9aa7-378b-7abc-8aaa-6168f8f8fc32" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c9aa7-378b-7e09-932a-ddb3c8368706" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019c9aa7-378b-7daa-9735-51ed93fa3bed" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019c9aa7-378b-7e09-932a-ddb3c8368706" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_019c9aa7-378b-73bf-abd0-a25c34b84e34" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019c9aa7-378b-7daa-9735-51ed93fa3bed" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_019c9aa7-378b-73bf-abd0-a25c34b84e34" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019c9aa7-378b-75b4-a9c6-e0db7e6cb2e4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019c9aa7-378b-7daa-9735-51ed93fa3bed" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019c9aa7-378b-75b4-a9c6-e0db7e6cb2e4" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.grainger.com/role/DEBTLongTermDebtInstrumentsDetails" xlink:type="simple" xlink:href="gww-20260331.xsd#DEBTLongTermDebtInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.grainger.com/role/DEBTLongTermDebtInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7db8-ae81-e687af83daf8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7db8-ae81-e687af83daf8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019c9aa7-378c-739d-8232-586716b202ff" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7db8-ae81-e687af83daf8" xlink:to="loc_us-gaap_DebtInstrumentAxis_019c9aa7-378c-739d-8232-586716b202ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-739d-8232-586716b202ff_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019c9aa7-378c-739d-8232-586716b202ff" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-739d-8232-586716b202ff_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-7f95-b981-6c4a5c22d094" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019c9aa7-378c-739d-8232-586716b202ff" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-7f95-b981-6c4a5c22d094" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_UnsecuredSeniorNotes4.60Member_019c9aa7-378c-7acc-a7f2-143bb462ac61" xlink:href="gww-20260331.xsd#gww_UnsecuredSeniorNotes4.60Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-7f95-b981-6c4a5c22d094" xlink:to="loc_gww_UnsecuredSeniorNotes4.60Member_019c9aa7-378c-7acc-a7f2-143bb462ac61" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_UnsecuredSeniorNotes4.45Member_019c9aa7-378c-7658-97fe-991d07b4790e" xlink:href="gww-20260331.xsd#gww_UnsecuredSeniorNotes4.45Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-7f95-b981-6c4a5c22d094" xlink:to="loc_gww_UnsecuredSeniorNotes4.45Member_019c9aa7-378c-7658-97fe-991d07b4790e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_UnsecuredSeniorNotes3.75Member_019c9aa7-378c-723c-87d6-f0759b07b022" xlink:href="gww-20260331.xsd#gww_UnsecuredSeniorNotes3.75Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-7f95-b981-6c4a5c22d094" xlink:to="loc_gww_UnsecuredSeniorNotes3.75Member_019c9aa7-378c-723c-87d6-f0759b07b022" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_UnsecuredSeniorNotes4.20Member_019c9aa7-378c-7771-a4db-46e9dd3123b2" xlink:href="gww-20260331.xsd#gww_UnsecuredSeniorNotes4.20Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-7f95-b981-6c4a5c22d094" xlink:to="loc_gww_UnsecuredSeniorNotes4.20Member_019c9aa7-378c-7771-a4db-46e9dd3123b2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019c9aa7-378c-789c-8c65-76a1d02ce68b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7db8-ae81-e687af83daf8" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019c9aa7-378c-789c-8c65-76a1d02ce68b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-789c-8c65-76a1d02ce68b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019c9aa7-378c-789c-8c65-76a1d02ce68b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-789c-8c65-76a1d02ce68b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-78d1-9ac1-0566b80b0611" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019c9aa7-378c-789c-8c65-76a1d02ce68b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-78d1-9ac1-0566b80b0611" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019c9aa7-378c-7c1e-9be5-d8e110a5bf91" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-78d1-9ac1-0566b80b0611" xlink:to="loc_us-gaap_SeniorNotesMember_019c9aa7-378c-7c1e-9be5-d8e110a5bf91" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019c9aa7-378c-7786-bf34-cfb63aed28ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-78d1-9ac1-0566b80b0611" xlink:to="loc_us-gaap_LineOfCreditMember_019c9aa7-378c-7786-bf34-cfb63aed28ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_019c9aa7-378c-7d68-b04c-01b3707be3ae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7db8-ae81-e687af83daf8" xlink:to="loc_us-gaap_ShortTermDebtTypeAxis_019c9aa7-378c-7d68-b04c-01b3707be3ae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_019c9aa7-378c-7d68-b04c-01b3707be3ae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_019c9aa7-378c-7d68-b04c-01b3707be3ae" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_019c9aa7-378c-7d68-b04c-01b3707be3ae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_019c9aa7-378c-726a-be9d-c3bb43f59508" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_019c9aa7-378c-7d68-b04c-01b3707be3ae" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_019c9aa7-378c-726a-be9d-c3bb43f59508" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019c9aa7-378c-775e-9cb9-2d73db3a3927" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_019c9aa7-378c-726a-be9d-c3bb43f59508" xlink:to="loc_us-gaap_SeniorNotesMember_019c9aa7-378c-775e-9cb9-2d73db3a3927" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_OtherShortTermDebtMember_019c9aa7-378c-70aa-95dc-02f44d4048b4" xlink:href="gww-20260331.xsd#gww_OtherShortTermDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_019c9aa7-378c-726a-be9d-c3bb43f59508" xlink:to="loc_gww_OtherShortTermDebtMember_019c9aa7-378c-70aa-95dc-02f44d4048b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019c9aa7-378c-72a9-ad27-25fca8c7e2bf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7db8-ae81-e687af83daf8" xlink:to="loc_us-gaap_CreditFacilityAxis_019c9aa7-378c-72a9-ad27-25fca8c7e2bf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019c9aa7-378c-72a9-ad27-25fca8c7e2bf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019c9aa7-378c-72a9-ad27-25fca8c7e2bf" xlink:to="loc_us-gaap_CreditFacilityDomain_019c9aa7-378c-72a9-ad27-25fca8c7e2bf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019c9aa7-378c-718e-90f8-3c799e7bd40f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019c9aa7-378c-72a9-ad27-25fca8c7e2bf" xlink:to="loc_us-gaap_CreditFacilityDomain_019c9aa7-378c-718e-90f8-3c799e7bd40f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019c9aa7-378c-71b4-a851-bcd3efecee1c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019c9aa7-378c-718e-90f8-3c799e7bd40f" xlink:to="loc_us-gaap_SecuredDebtMember_019c9aa7-378c-71b4-a851-bcd3efecee1c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019c9aa7-378c-7c6a-a95c-d3b3ca76891f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019c9aa7-378c-7c6a-a95c-d3b3ca76891f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019c9aa7-378c-7c31-96a4-d486895b05af" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019c9aa7-378c-7c31-96a4-d486895b05af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_019c9aa7-378c-73eb-94a8-d918a8b48d0b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_019c9aa7-378c-73eb-94a8-d918a8b48d0b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019c9aa7-378c-700d-9a9e-b2964095a8f0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_019c9aa7-378c-700d-9a9e-b2964095a8f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_OtherShortTermDebt_019c9aa7-378c-7b5c-89f9-9da0765b5ab8" xlink:href="gww-20260331.xsd#gww_OtherShortTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_gww_OtherShortTermDebt_019c9aa7-378c-7b5c-89f9-9da0765b5ab8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_019c9aa7-378c-7ba6-9794-9ca493126ff6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_us-gaap_LongTermDebtCurrent_019c9aa7-378c-7ba6-9794-9ca493126ff6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019c9aa7-378c-7282-b35b-821e9b759bbd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_us-gaap_LongTermDebt_019c9aa7-378c-7282-b35b-821e9b759bbd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_LongTermDebtGrossFairValueDisclosure_019c9aa7-378c-79fd-bcaa-2593a6bdbc9e" xlink:href="gww-20260331.xsd#gww_LongTermDebtGrossFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_gww_LongTermDebtGrossFairValueDisclosure_019c9aa7-378c-79fd-bcaa-2593a6bdbc9e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_DebtIssuanceCostNetFairValue_019c9aa7-378c-7f4a-9c15-bb15a6b1bf9a" xlink:href="gww-20260331.xsd#gww_DebtIssuanceCostNetFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_gww_DebtIssuanceCostNetFairValue_019c9aa7-378c-7f4a-9c15-bb15a6b1bf9a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_LongTermDebtExcludingCurrentMaturitiesFairValueDisclosure_019c9aa7-378c-7542-9fc4-f55d2bbee439" xlink:href="gww-20260331.xsd#gww_LongTermDebtExcludingCurrentMaturitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_gww_LongTermDebtExcludingCurrentMaturitiesFairValueDisclosure_019c9aa7-378c-7542-9fc4-f55d2bbee439" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_OtherShortTermDebtFairValue_019c9aa7-378c-7c34-a93b-392df19f7146" xlink:href="gww-20260331.xsd#gww_OtherShortTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_gww_OtherShortTermDebtFairValue_019c9aa7-378c-7c34-a93b-392df19f7146" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_LongTermDebtCurrentMaturitiesFairValueDisclosure_019c9aa7-378c-72a0-8fce-09173174a0dd" xlink:href="gww-20260331.xsd#gww_LongTermDebtCurrentMaturitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_gww_LongTermDebtCurrentMaturitiesFairValueDisclosure_019c9aa7-378c-72a0-8fce-09173174a0dd" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_019c9aa7-378c-7dd6-860b-da500c2ff816" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7fca-a335-b33a5a613abc" xlink:to="loc_us-gaap_LongTermDebtFairValue_019c9aa7-378c-7dd6-860b-da500c2ff816" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.grainger.com/role/DEBTNarrativeDetails" xlink:type="simple" xlink:href="gww-20260331.xsd#DEBTNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.grainger.com/role/DEBTNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7db5-b469-03f744a254f1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7ace-b9da-dbf51e00af98" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7db5-b469-03f744a254f1" xlink:to="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7ace-b9da-dbf51e00af98" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019c9aa7-378c-7e6c-85fc-25be27a8398d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7ace-b9da-dbf51e00af98" xlink:to="loc_us-gaap_DebtInstrumentAxis_019c9aa7-378c-7e6c-85fc-25be27a8398d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-7e6c-85fc-25be27a8398d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019c9aa7-378c-7e6c-85fc-25be27a8398d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-7e6c-85fc-25be27a8398d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-767f-8162-94661c5386d9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019c9aa7-378c-7e6c-85fc-25be27a8398d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-767f-8162-94661c5386d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_UnsecuredSeniorNotes185Member_019c9aa7-378c-7d74-8d35-cebbca57d70f" xlink:href="gww-20260331.xsd#gww_UnsecuredSeniorNotes185Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019c9aa7-378c-767f-8162-94661c5386d9" xlink:to="loc_gww_UnsecuredSeniorNotes185Member_019c9aa7-378c-7d74-8d35-cebbca57d70f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019c9aa7-378c-7e67-889b-3bea4c55861f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7ace-b9da-dbf51e00af98" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019c9aa7-378c-7e67-889b-3bea4c55861f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-7e67-889b-3bea4c55861f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019c9aa7-378c-7e67-889b-3bea4c55861f" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-7e67-889b-3bea4c55861f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-7ba7-a34e-f66bf1c7fb4f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019c9aa7-378c-7e67-889b-3bea4c55861f" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-7ba7-a34e-f66bf1c7fb4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019c9aa7-378c-76cb-8b16-e1e8111dcb63" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-7ba7-a34e-f66bf1c7fb4f" xlink:to="loc_us-gaap_SeniorNotesMember_019c9aa7-378c-76cb-8b16-e1e8111dcb63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019c9aa7-378c-78c7-80d3-5c1663845d0f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019c9aa7-378c-7ba7-a34e-f66bf1c7fb4f" xlink:to="loc_us-gaap_LineOfCreditMember_019c9aa7-378c-78c7-80d3-5c1663845d0f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019c9aa7-378c-737f-a25f-614fbf300819" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7ace-b9da-dbf51e00af98" xlink:to="loc_us-gaap_CreditFacilityAxis_019c9aa7-378c-737f-a25f-614fbf300819" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019c9aa7-378c-737f-a25f-614fbf300819_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019c9aa7-378c-737f-a25f-614fbf300819" xlink:to="loc_us-gaap_CreditFacilityDomain_019c9aa7-378c-737f-a25f-614fbf300819_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019c9aa7-378c-785f-8607-edd6b0d34d25" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019c9aa7-378c-737f-a25f-614fbf300819" xlink:to="loc_us-gaap_CreditFacilityDomain_019c9aa7-378c-785f-8607-edd6b0d34d25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019c9aa7-378c-7236-81f4-303dbdadcb9e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019c9aa7-378c-785f-8607-edd6b0d34d25" xlink:to="loc_us-gaap_SecuredDebtMember_019c9aa7-378c-7236-81f4-303dbdadcb9e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_019dab35-3591-79c1-aa32-31e1c1b1b777" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019c9aa7-378c-7ace-b9da-dbf51e00af98" xlink:to="loc_us-gaap_ShortTermDebtTypeAxis_019dab35-3591-79c1-aa32-31e1c1b1b777" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_019dab35-3591-79c1-aa32-31e1c1b1b777_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_019dab35-3591-79c1-aa32-31e1c1b1b777" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_019dab35-3591-79c1-aa32-31e1c1b1b777_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_019dab35-3591-7169-acd2-791445c9fe62" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_019dab35-3591-79c1-aa32-31e1c1b1b777" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_019dab35-3591-7169-acd2-791445c9fe62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019dab35-8825-773d-8231-e5d9ef0be55a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_019dab35-3591-7169-acd2-791445c9fe62" xlink:to="loc_us-gaap_SeniorNotesMember_019dab35-8825-773d-8231-e5d9ef0be55a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019c9aa7-378c-7767-9255-b7976faa4d03" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7db5-b469-03f744a254f1" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019c9aa7-378c-7767-9255-b7976faa4d03" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRepaidPrincipal_019dab35-3591-7e92-9f23-1697da741ca1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRepaidPrincipal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7db5-b469-03f744a254f1" xlink:to="loc_us-gaap_DebtInstrumentRepaidPrincipal_019dab35-3591-7e92-9f23-1697da741ca1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019c9aa7-378c-7c9e-8b43-a582d84acfff" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7db5-b469-03f744a254f1" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019c9aa7-378c-7c9e-8b43-a582d84acfff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019c9aa7-378c-741d-9d32-85e5c60a8adc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7db5-b469-03f744a254f1" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019c9aa7-378c-741d-9d32-85e5c60a8adc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_019c9aa7-378c-7aa8-b347-dd12f7f47f01" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019c9aa7-378c-7db5-b469-03f744a254f1" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_019c9aa7-378c-7aa8-b347-dd12f7f47f01" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.grainger.com/role/SEGMENTINFORMATIONDetails" xlink:type="simple" xlink:href="gww-20260331.xsd#SEGMENTINFORMATIONDetails"/>
  <link:definitionLink xlink:role="http://www.grainger.com/role/SEGMENTINFORMATIONDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019c9aa7-378c-79d1-a2e4-2c864dfe912c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019c9aa7-378c-7b10-ace9-a23d8bd1a48b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019c9aa7-378c-79d1-a2e4-2c864dfe912c" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019c9aa7-378c-7b10-ace9-a23d8bd1a48b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378c-79c4-a4e4-6db8514d2dc1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019c9aa7-378c-7b10-ace9-a23d8bd1a48b" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378c-79c4-a4e4-6db8514d2dc1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019c9aa7-378c-79c4-a4e4-6db8514d2dc1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378c-79c4-a4e4-6db8514d2dc1" xlink:to="loc_us-gaap_SegmentDomain_019c9aa7-378c-79c4-a4e4-6db8514d2dc1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019c9aa7-378c-7a43-bbc2-6c5a7a3cf903" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019c9aa7-378c-79c4-a4e4-6db8514d2dc1" xlink:to="loc_us-gaap_SegmentDomain_019c9aa7-378c-7a43-bbc2-6c5a7a3cf903" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_HighTouchSolutionsNAMember_019c9aa7-378c-7aa4-976b-898a168c6ff5" xlink:href="gww-20260331.xsd#gww_HighTouchSolutionsNAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019c9aa7-378c-7a43-bbc2-6c5a7a3cf903" xlink:to="loc_gww_HighTouchSolutionsNAMember_019c9aa7-378c-7aa4-976b-898a168c6ff5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_EndlessAssortmentMember_019c9aa7-378c-7c89-8481-13cc0f4bdf01" xlink:href="gww-20260331.xsd#gww_EndlessAssortmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019c9aa7-378c-7a43-bbc2-6c5a7a3cf903" xlink:to="loc_gww_EndlessAssortmentMember_019c9aa7-378c-7c89-8481-13cc0f4bdf01" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_OtherMember_019c9aa7-378c-78c2-9c33-e3641c8bf38d" xlink:href="gww-20260331.xsd#gww_OtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019c9aa7-378c-7a43-bbc2-6c5a7a3cf903" xlink:to="loc_gww_OtherMember_019c9aa7-378c-78c2-9c33-e3641c8bf38d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019c9aa7-378c-78a9-8e18-3cc2dbe2c039" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019c9aa7-378c-7b10-ace9-a23d8bd1a48b" xlink:to="loc_srt_ConsolidationItemsAxis_019c9aa7-378c-78a9-8e18-3cc2dbe2c039" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019c9aa7-378c-78a9-8e18-3cc2dbe2c039_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019c9aa7-378c-78a9-8e18-3cc2dbe2c039" xlink:to="loc_srt_ConsolidationItemsDomain_019c9aa7-378c-78a9-8e18-3cc2dbe2c039_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019c9aa7-378c-7569-bf71-4a2134ea3ea7" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019c9aa7-378c-78a9-8e18-3cc2dbe2c039" xlink:to="loc_srt_ConsolidationItemsDomain_019c9aa7-378c-7569-bf71-4a2134ea3ea7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019c9aa7-378c-78a9-b9d6-4f8d91eeaf4c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019c9aa7-378c-7569-bf71-4a2134ea3ea7" xlink:to="loc_us-gaap_OperatingSegmentsMember_019c9aa7-378c-78a9-b9d6-4f8d91eeaf4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019c9aa7-378c-70fe-b5d2-55e36961b2de" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019c9aa7-378c-7569-bf71-4a2134ea3ea7" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019c9aa7-378c-70fe-b5d2-55e36961b2de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019c9aa7-378c-7b7d-b8cc-0f338118b9da" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019c9aa7-378c-7b10-ace9-a23d8bd1a48b" xlink:to="loc_srt_StatementGeographicalAxis_019c9aa7-378c-7b7d-b8cc-0f338118b9da" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019c9aa7-378c-7b7d-b8cc-0f338118b9da_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019c9aa7-378c-7b7d-b8cc-0f338118b9da" xlink:to="loc_srt_SegmentGeographicalDomain_019c9aa7-378c-7b7d-b8cc-0f338118b9da_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019c9aa7-378c-77ca-828a-82eb682f00d1" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019c9aa7-378c-7b7d-b8cc-0f338118b9da" xlink:to="loc_srt_SegmentGeographicalDomain_019c9aa7-378c-77ca-828a-82eb682f00d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019c9aa7-378c-7b76-877e-528108e5209e" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019c9aa7-378c-77ca-828a-82eb682f00d1" xlink:to="loc_country_US_019c9aa7-378c-7b76-877e-528108e5209e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_JP_019c9aa7-378c-7e44-a3d8-32f28ab7c5f8" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_JP"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019c9aa7-378c-77ca-828a-82eb682f00d1" xlink:to="loc_country_JP_019c9aa7-378c-7e44-a3d8-32f28ab7c5f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CA_019c9aa7-378c-7dc0-873f-940c949643fa" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_CA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019c9aa7-378c-77ca-828a-82eb682f00d1" xlink:to="loc_country_CA_019c9aa7-378c-7dc0-873f-940c949643fa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_OtherForeignCountriesMember_019c9aa7-378c-794a-a5bd-525a26f25e41" xlink:href="gww-20260331.xsd#gww_OtherForeignCountriesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019c9aa7-378c-77ca-828a-82eb682f00d1" xlink:to="loc_gww_OtherForeignCountriesMember_019c9aa7-378c-794a-a5bd-525a26f25e41" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_019c9aa7-378c-78e5-9c23-808543afad43" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019c9aa7-378c-79d1-a2e4-2c864dfe912c" xlink:to="loc_us-gaap_NumberOfReportableSegments_019c9aa7-378c-78e5-9c23-808543afad43" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gww_SegmentReportingInformationAssetsAbstract_019c9aa7-378c-7e1a-a0a0-715d184dd0cd" xlink:href="gww-20260331.xsd#gww_SegmentReportingInformationAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019c9aa7-378c-79d1-a2e4-2c864dfe912c" xlink:to="loc_gww_SegmentReportingInformationAssetsAbstract_019c9aa7-378c-7e1a-a0a0-715d184dd0cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019c9aa7-378c-7a29-92d0-57ba088a9929" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_gww_SegmentReportingInformationAssetsAbstract_019c9aa7-378c-7e1a-a0a0-715d184dd0cd" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019c9aa7-378c-7a29-92d0-57ba088a9929" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019c9aa7-378c-795b-9271-4665a4a18b26" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_gww_SegmentReportingInformationAssetsAbstract_019c9aa7-378c-7e1a-a0a0-715d184dd0cd" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019c9aa7-378c-795b-9271-4665a4a18b26" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019c9aa7-378c-78f5-a31e-512c540b1aff" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_gww_SegmentReportingInformationAssetsAbstract_019c9aa7-378c-7e1a-a0a0-715d184dd0cd" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019c9aa7-378c-78f5-a31e-512c540b1aff" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019c9aa7-378c-7720-9d27-81e0fecd772f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_gww_SegmentReportingInformationAssetsAbstract_019c9aa7-378c-7e1a-a0a0-715d184dd0cd" xlink:to="loc_us-gaap_OperatingIncomeLoss_019c9aa7-378c-7720-9d27-81e0fecd772f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019c9aa7-378c-7515-891d-525991e5c789" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_gww_SegmentReportingInformationAssetsAbstract_019c9aa7-378c-7e1a-a0a0-715d184dd0cd" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019c9aa7-378c-7515-891d-525991e5c789" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.grainger.com/role/SUBSEQUENTEVENTSDetails" xlink:type="simple" xlink:href="gww-20260331.xsd#SUBSEQUENTEVENTSDetails"/>
  <link:definitionLink xlink:role="http://www.grainger.com/role/SUBSEQUENTEVENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_019c9aa7-378c-7868-bb87-9893ccf7a2aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_019c9aa7-378c-7150-b938-c1e4d601a843" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_019c9aa7-378c-7868-bb87-9893ccf7a2aa" xlink:to="loc_us-gaap_SubsequentEventTable_019c9aa7-378c-7150-b938-c1e4d601a843" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019c9aa7-378c-718c-a005-1ecd98b24a99" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019c9aa7-378c-7150-b938-c1e4d601a843" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019c9aa7-378c-718c-a005-1ecd98b24a99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019c9aa7-378c-718c-a005-1ecd98b24a99_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019c9aa7-378c-718c-a005-1ecd98b24a99" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019c9aa7-378c-718c-a005-1ecd98b24a99_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019c9aa7-378c-7d68-b310-28a78019b904" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019c9aa7-378c-718c-a005-1ecd98b24a99" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019c9aa7-378c-7d68-b310-28a78019b904" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019c9aa7-378c-7399-b5ee-90198a4c512c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019c9aa7-378c-7d68-b310-28a78019b904" xlink:to="loc_us-gaap_SubsequentEventMember_019c9aa7-378c-7399-b5ee-90198a4c512c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableAmountPerShare_019c9aa7-378c-7a0a-8845-ee9899f0e9c5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableAmountPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019c9aa7-378c-7868-bb87-9893ccf7a2aa" xlink:to="loc_us-gaap_DividendsPayableAmountPerShare_019c9aa7-378c-7a0a-8845-ee9899f0e9c5" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
