<?xml version="1.0" encoding="US-ASCII"?>
<!--XBRL Document Created with Wdesk from Workiva, formerly WebFilings-->
<!-- -->
<linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <roleRef roleURI="http://www.dycomind.com/role/AccountsReceivable" xlink:href="dy-20150425.xsd#AccountsReceivable" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/AccountsReceivableDetails" xlink:href="dy-20150425.xsd#AccountsReceivableDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/AccountsReceivableTables" xlink:href="dy-20150425.xsd#AccountsReceivableTables" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/AccruedInsuranceClaims" xlink:href="dy-20150425.xsd#AccruedInsuranceClaims" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/AccruedInsuranceClaimsDetails" xlink:href="dy-20150425.xsd#AccruedInsuranceClaimsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/Acquisitions" xlink:href="dy-20150425.xsd#Acquisitions" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/AcquisitionsDetails" xlink:href="dy-20150425.xsd#AcquisitionsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/BasisOfPresentationAndAccountingPolicies" xlink:href="dy-20150425.xsd#BasisOfPresentationAndAccountingPolicies" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/BasisOfPresentationAndAccountingPoliciesDetails" xlink:href="dy-20150425.xsd#BasisOfPresentationAndAccountingPoliciesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/BasisOfPresentationAndAccountingPoliciesPolicies" xlink:href="dy-20150425.xsd#BasisOfPresentationAndAccountingPoliciesPolicies" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/CapitalStock" xlink:href="dy-20150425.xsd#CapitalStock" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/CapitalStockDetails" xlink:href="dy-20150425.xsd#CapitalStockDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/CommitmentsAndContingencies" xlink:href="dy-20150425.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/CommitmentsAndContingenciesDetails" xlink:href="dy-20150425.xsd#CommitmentsAndContingenciesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ComputationOfEarningsPerCommonShare" xlink:href="dy-20150425.xsd#ComputationOfEarningsPerCommonShare" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ComputationOfEarningsPerCommonShareDetails" xlink:href="dy-20150425.xsd#ComputationOfEarningsPerCommonShareDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ComputationOfEarningsPerCommonShareTables" xlink:href="dy-20150425.xsd#ComputationOfEarningsPerCommonShareTables" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ConcentrationOfCreditRisk" xlink:href="dy-20150425.xsd#ConcentrationOfCreditRisk" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ConcentrationOfCreditRiskDetails" xlink:href="dy-20150425.xsd#ConcentrationOfCreditRiskDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ConcentrationOfCreditRiskTables" xlink:href="dy-20150425.xsd#ConcentrationOfCreditRiskTables" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ConsolidatedBalanceSheets" xlink:href="dy-20150425.xsd#ConsolidatedBalanceSheets" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:href="dy-20150425.xsd#ConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="dy-20150425.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:href="dy-20150425.xsd#ConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ConsolidatedStatementsOfOperations" xlink:href="dy-20150425.xsd#ConsolidatedStatementsOfOperations" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/ConsolidatedStatementsOfOperationsParenthetical" xlink:href="dy-20150425.xsd#ConsolidatedStatementsOfOperationsParenthetical" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/CostsAndEstimatedEarningsInExcessOfBillings" xlink:href="dy-20150425.xsd#CostsAndEstimatedEarningsInExcessOfBillings" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/CostsAndEstimatedEarningsInExcessOfBillingsDetails" xlink:href="dy-20150425.xsd#CostsAndEstimatedEarningsInExcessOfBillingsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/CostsAndEstimatedEarningsInExcessOfBillingsTables" xlink:href="dy-20150425.xsd#CostsAndEstimatedEarningsInExcessOfBillingsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/Debt" xlink:href="dy-20150425.xsd#Debt" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/DebtDetails" xlink:href="dy-20150425.xsd#DebtDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/DebtOutstandingDetails" xlink:href="dy-20150425.xsd#DebtOutstandingDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/DebtTables" xlink:href="dy-20150425.xsd#DebtTables" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/DocumentAndEntityInformation" xlink:href="dy-20150425.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/GoodwillAndIntangibleAssets" xlink:href="dy-20150425.xsd#GoodwillAndIntangibleAssets" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/GoodwillAndIntangibleAssetsChangesInCarryingAmountOfGoodwillDetails" xlink:href="dy-20150425.xsd#GoodwillAndIntangibleAssetsChangesInCarryingAmountOfGoodwillDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/GoodwillAndIntangibleAssetsDetails" xlink:href="dy-20150425.xsd#GoodwillAndIntangibleAssetsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/GoodwillAndIntangibleAssetsFutureAmortizationExpenseDetails" xlink:href="dy-20150425.xsd#GoodwillAndIntangibleAssetsFutureAmortizationExpenseDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/GoodwillAndIntangibleAssetsIntangibleAssetsDetails" xlink:href="dy-20150425.xsd#GoodwillAndIntangibleAssetsIntangibleAssetsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/GoodwillAndIntangibleAssetsTables" xlink:href="dy-20150425.xsd#GoodwillAndIntangibleAssetsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/IncomeTaxes" xlink:href="dy-20150425.xsd#IncomeTaxes" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/IncomeTaxesDetails" xlink:href="dy-20150425.xsd#IncomeTaxesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/OtherAccruedLiabilities" xlink:href="dy-20150425.xsd#OtherAccruedLiabilities" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/OtherAccruedLiabilitiesDetails" xlink:href="dy-20150425.xsd#OtherAccruedLiabilitiesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/OtherAccruedLiabilitiesTables" xlink:href="dy-20150425.xsd#OtherAccruedLiabilitiesTables" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/OtherIncomeNet" xlink:href="dy-20150425.xsd#OtherIncomeNet" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/OtherIncomeNetDetails" xlink:href="dy-20150425.xsd#OtherIncomeNetDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/OtherIncomeNetTables" xlink:href="dy-20150425.xsd#OtherIncomeNetTables" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/PropertyAndEquipment" xlink:href="dy-20150425.xsd#PropertyAndEquipment" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/PropertyAndEquipmentDetails" xlink:href="dy-20150425.xsd#PropertyAndEquipmentDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/PropertyAndEquipmentTables" xlink:href="dy-20150425.xsd#PropertyAndEquipmentTables" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/RelatedPartyTransactions" xlink:href="dy-20150425.xsd#RelatedPartyTransactions" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/RelatedPartyTransactionsDetails" xlink:href="dy-20150425.xsd#RelatedPartyTransactionsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/RelatedPartyTransactionsTables" xlink:href="dy-20150425.xsd#RelatedPartyTransactionsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/StockBasedAwards" xlink:href="dy-20150425.xsd#StockBasedAwards" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/StockBasedAwardsDetails" xlink:href="dy-20150425.xsd#StockBasedAwardsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/StockBasedAwardsRsusAndPerformanceRsusDetails" xlink:href="dy-20150425.xsd#StockBasedAwardsRsusAndPerformanceRsusDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/StockBasedAwardsStockOptionsDetails" xlink:href="dy-20150425.xsd#StockBasedAwardsStockOptionsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/StockBasedAwardsTables" xlink:href="dy-20150425.xsd#StockBasedAwardsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/StockBasedAwardsTaxBenefitRecognizedDetails" xlink:href="dy-20150425.xsd#StockBasedAwardsTaxBenefitRecognizedDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatements" xlink:href="dy-20150425.xsd#SupplementalConsolidatingFinancialStatements" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatementsBalanceSheetDetails" xlink:href="dy-20150425.xsd#SupplementalConsolidatingFinancialStatementsBalanceSheetDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatementsCashFlowsDetails" xlink:href="dy-20150425.xsd#SupplementalConsolidatingFinancialStatementsCashFlowsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatementsDetails" xlink:href="dy-20150425.xsd#SupplementalConsolidatingFinancialStatementsDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatementsIncomeStatementDetails" xlink:href="dy-20150425.xsd#SupplementalConsolidatingFinancialStatementsIncomeStatementDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatementsTables" xlink:href="dy-20150425.xsd#SupplementalConsolidatingFinancialStatementsTables" xlink:type="simple" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" />
  <arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" />
  <definitionLink xlink:role="http://www.dycomind.com/role/AccountsReceivable" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/AccountsReceivableDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_4815B89852EBD49713FF7909CEB196C8" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_A0D41B788C5A6F1E7F6F7909CEB1915E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_4815B89852EBD49713FF7909CEB196C8" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_A0D41B788C5A6F1E7F6F7909CEB1915E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis_F794F83F09FA9A28CE607909CEB1D0F9" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_A0D41B788C5A6F1E7F6F7909CEB1915E" xlink:to="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis_F794F83F09FA9A28CE607909CEB1D0F9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LegalEntityTypeOfCounterpartyDomain" xlink:label="loc_us-gaap_LegalEntityTypeOfCounterpartyDomain_C72736A7FC7840B95D977909CEB13AAB_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis_F794F83F09FA9A28CE607909CEB1D0F9" xlink:to="loc_us-gaap_LegalEntityTypeOfCounterpartyDomain_C72736A7FC7840B95D977909CEB13AAB_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LegalEntityTypeOfCounterpartyDomain" xlink:label="loc_us-gaap_LegalEntityTypeOfCounterpartyDomain_C72736A7FC7840B95D977909CEB13AAB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis_F794F83F09FA9A28CE607909CEB1D0F9" xlink:to="loc_us-gaap_LegalEntityTypeOfCounterpartyDomain_C72736A7FC7840B95D977909CEB13AAB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CorporationMember" xlink:label="loc_us-gaap_CorporationMember_CD03D17CF7BED8978F537909CEB1C829" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LegalEntityTypeOfCounterpartyDomain_C72736A7FC7840B95D977909CEB13AAB" xlink:to="loc_us-gaap_CorporationMember_CD03D17CF7BED8978F537909CEB1C829" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_856955EF70DCFBEFEE937909CEB18EEB" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_A0D41B788C5A6F1E7F6F7909CEB1915E" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_856955EF70DCFBEFEE937909CEB18EEB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_26F28322A7829E14E6D17909CEB17738_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_856955EF70DCFBEFEE937909CEB18EEB" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_26F28322A7829E14E6D17909CEB17738_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_26F28322A7829E14E6D17909CEB17738" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_856955EF70DCFBEFEE937909CEB18EEB" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_26F28322A7829E14E6D17909CEB17738" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_BDF291808A8298D4D1C67909CEB1DD5F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_26F28322A7829E14E6D17909CEB17738" xlink:to="loc_us-gaap_SubsequentEventMember_BDF291808A8298D4D1C67909CEB1DD5F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BilledContractReceivables" xlink:label="loc_us-gaap_BilledContractReceivables_3D0E284375B81D0898DF7909CEB25753" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_4815B89852EBD49713FF7909CEB196C8" xlink:to="loc_us-gaap_BilledContractReceivables_3D0E284375B81D0898DF7909CEB25753" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_ContractReceivableRetainageAndOtherReceivables" xlink:label="loc_dy_ContractReceivableRetainageAndOtherReceivables_959F52BDF7112357CBCA7909CEB2D4E4" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_4815B89852EBD49713FF7909CEB196C8" xlink:to="loc_dy_ContractReceivableRetainageAndOtherReceivables_959F52BDF7112357CBCA7909CEB2D4E4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountsReceivableGross" xlink:label="loc_us-gaap_AccountsReceivableGross_1C57F86B24306D7F3B567909CEB207C9" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_4815B89852EBD49713FF7909CEB196C8" xlink:to="loc_us-gaap_AccountsReceivableGross_1C57F86B24306D7F3B567909CEB207C9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_D13919FE6C52650CF44A7909CEB22FAB" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_4815B89852EBD49713FF7909CEB196C8" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_D13919FE6C52650CF44A7909CEB22FAB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountsReceivableNet" xlink:label="loc_us-gaap_AccountsReceivableNet_19E70E37D5E0B2DD1A287909CEB204A5" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_4815B89852EBD49713FF7909CEB196C8" xlink:to="loc_us-gaap_AccountsReceivableNet_19E70E37D5E0B2DD1A287909CEB204A5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InvestmentsAndOtherNoncurrentAssets" xlink:label="loc_us-gaap_InvestmentsAndOtherNoncurrentAssets_7588160C98C5A6913239790A4D49964C" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_4815B89852EBD49713FF7909CEB196C8" xlink:to="loc_us-gaap_InvestmentsAndOtherNoncurrentAssets_7588160C98C5A6913239790A4D49964C" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_CollectionofPastDueReceivableBalance" xlink:label="loc_dy_CollectionofPastDueReceivableBalance_CE01FB60A6A6C77AB7087909CEB2286D" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_4815B89852EBD49713FF7909CEB196C8" xlink:to="loc_dy_CollectionofPastDueReceivableBalance_CE01FB60A6A6C77AB7087909CEB2286D" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/AccountsReceivableTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/AccruedInsuranceClaims" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/AccruedInsuranceClaimsDetails" xlink:type="extended">
    <loc xlink:href="dy-20150425.xsd#dy_AccruedInsuranceClaimsLineItems" xlink:label="loc_dy_AccruedInsuranceClaimsLineItems_A82D402881F15D017D1E700C45F9B38E" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_AE14702DD5327CFB7AB7700C45F9B93A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dy_AccruedInsuranceClaimsLineItems_A82D402881F15D017D1E700C45F9B38E" xlink:to="loc_us-gaap_StatementTable_AE14702DD5327CFB7AB7700C45F9B93A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_F43EB5E0F289447074C8700C45F9948A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_AE14702DD5327CFB7AB7700C45F9B93A" xlink:to="loc_us-gaap_RangeAxis_F43EB5E0F289447074C8700C45F9948A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_2CBC35A4AE43F468DF2C700C45F99620_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_F43EB5E0F289447074C8700C45F9948A" xlink:to="loc_us-gaap_RangeMember_2CBC35A4AE43F468DF2C700C45F99620_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_2CBC35A4AE43F468DF2C700C45F99620" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_F43EB5E0F289447074C8700C45F9948A" xlink:to="loc_us-gaap_RangeMember_2CBC35A4AE43F468DF2C700C45F99620" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_F606E18E7F98031FECCD700C45F9792E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_2CBC35A4AE43F468DF2C700C45F99620" xlink:to="loc_us-gaap_MaximumMember_F606E18E7F98031FECCD700C45F9792E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_6ED006786864B52FE0C0700C45F98075" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_AE14702DD5327CFB7AB7700C45F9B93A" xlink:to="loc_us-gaap_StatementScenarioAxis_6ED006786864B52FE0C0700C45F98075" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_FE0FD3D67DE0E45C56AC700C45F9F6DB_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_6ED006786864B52FE0C0700C45F98075" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_FE0FD3D67DE0E45C56AC700C45F9F6DB_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_FE0FD3D67DE0E45C56AC700C45F9F6DB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_6ED006786864B52FE0C0700C45F98075" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_FE0FD3D67DE0E45C56AC700C45F9F6DB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScenarioForecastMember" xlink:label="loc_us-gaap_ScenarioForecastMember_E05A20FD35F6D19B1AA6700C45F9E730" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain_FE0FD3D67DE0E45C56AC700C45F9F6DB" xlink:to="loc_us-gaap_ScenarioForecastMember_E05A20FD35F6D19B1AA6700C45F9E730" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_AutomobileInsuranceLiabilityGeneralLiabilityAndWorkersCompensation" xlink:label="loc_dy_AutomobileInsuranceLiabilityGeneralLiabilityAndWorkersCompensation_ABF5CB642E0071AA9DD0700C45F97DDC" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_AccruedInsuranceClaimsLineItems_A82D402881F15D017D1E700C45F9B38E" xlink:to="loc_dy_AutomobileInsuranceLiabilityGeneralLiabilityAndWorkersCompensation_ABF5CB642E0071AA9DD0700C45F97DDC" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_AggregateStopLossCoverageforAutomobileLiabilityGeneralLiabilityandWorkersCompensationClaimsBeforeAdjustmentIncrease" xlink:label="loc_dy_AggregateStopLossCoverageforAutomobileLiabilityGeneralLiabilityandWorkersCompensationClaimsBeforeAdjustmentIncrease_50A623A79E38D2B8A752700C45F9500F" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_AccruedInsuranceClaimsLineItems_A82D402881F15D017D1E700C45F9B38E" xlink:to="loc_dy_AggregateStopLossCoverageforAutomobileLiabilityGeneralLiabilityandWorkersCompensationClaimsBeforeAdjustmentIncrease_50A623A79E38D2B8A752700C45F9500F" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_InsuranceLiabilityAnnualRetainedRiskOfLossUnderEmployeeHealthPlanPerParticipant" xlink:label="loc_dy_InsuranceLiabilityAnnualRetainedRiskOfLossUnderEmployeeHealthPlanPerParticipant_A2EF2ED602A5A32F5492700C45F9B03E" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_AccruedInsuranceClaimsLineItems_A82D402881F15D017D1E700C45F9B38E" xlink:to="loc_dy_InsuranceLiabilityAnnualRetainedRiskOfLossUnderEmployeeHealthPlanPerParticipant_A2EF2ED602A5A32F5492700C45F9B03E" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_InsuranceLiabilityRetainedRiskOfLossPerParticipantEmployeeHealthPlanClaimAmountsThatAggregateAcrossAllParticipants" xlink:label="loc_dy_InsuranceLiabilityRetainedRiskOfLossPerParticipantEmployeeHealthPlanClaimAmountsThatAggregateAcrossAllParticipants_B8A9274FED9BBF82DBA3700C45F95F31" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_AccruedInsuranceClaimsLineItems_A82D402881F15D017D1E700C45F9B38E" xlink:to="loc_dy_InsuranceLiabilityRetainedRiskOfLossPerParticipantEmployeeHealthPlanClaimAmountsThatAggregateAcrossAllParticipants_B8A9274FED9BBF82DBA3700C45F95F31" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_InsuranceLiabilityRetainedRiskOfLossEmployeeHealthPlanThreshold" xlink:label="loc_dy_InsuranceLiabilityRetainedRiskOfLossEmployeeHealthPlanThreshold_0BEE5906D18AB5D1063D700C45F96573" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_AccruedInsuranceClaimsLineItems_A82D402881F15D017D1E700C45F9B38E" xlink:to="loc_dy_InsuranceLiabilityRetainedRiskOfLossEmployeeHealthPlanThreshold_0BEE5906D18AB5D1063D700C45F96573" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccruedInsuranceCurrentAndNoncurrent" xlink:label="loc_us-gaap_AccruedInsuranceCurrentAndNoncurrent_0CBA87B7F2503AAC6107700C45F9ACD9" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_AccruedInsuranceClaimsLineItems_A82D402881F15D017D1E700C45F9B38E" xlink:to="loc_us-gaap_AccruedInsuranceCurrentAndNoncurrent_0CBA87B7F2503AAC6107700C45F9ACD9" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_AccruedInsuranceClaimsNoncurrent" xlink:label="loc_dy_AccruedInsuranceClaimsNoncurrent_468A8E29D11BB15456ED700C45F910FE" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_AccruedInsuranceClaimsLineItems_A82D402881F15D017D1E700C45F9B38E" xlink:to="loc_dy_AccruedInsuranceClaimsNoncurrent_468A8E29D11BB15456ED700C45F910FE" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/Acquisitions" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/AcquisitionsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_9E727A8D84F807EECF2471AFD63DAF7C" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_458F450971CD60C2DC2271AFD63CEDF3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E727A8D84F807EECF2471AFD63DAF7C" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_458F450971CD60C2DC2271AFD63CEDF3" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_0EF572DB1262866FA7E271AFD63CEECE" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_458F450971CD60C2DC2271AFD63CEDF3" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_0EF572DB1262866FA7E271AFD63CEECE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_70DFCE520263E1FFBF2871AFD63CD696_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_0EF572DB1262866FA7E271AFD63CEECE" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_70DFCE520263E1FFBF2871AFD63CD696_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_70DFCE520263E1FFBF2871AFD63CD696" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_0EF572DB1262866FA7E271AFD63CEECE" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_70DFCE520263E1FFBF2871AFD63CD696" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_HewittPowerCommunicationsIncMember" xlink:label="loc_dy_HewittPowerCommunicationsIncMember_4E1CA96AC7CE079BA6BE71AFD63CD7F0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_70DFCE520263E1FFBF2871AFD63CD696" xlink:to="loc_dy_HewittPowerCommunicationsIncMember_4E1CA96AC7CE079BA6BE71AFD63CD7F0" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_ConnectCableContractorsInc.andSystemsCommunicationsServicesInc.Member" xlink:label="loc_dy_ConnectCableContractorsInc.andSystemsCommunicationsServicesInc.Member_7DDEFA1927E4D6EEA08071BA97EAECCA" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_70DFCE520263E1FFBF2871AFD63CD696" xlink:to="loc_dy_ConnectCableContractorsInc.andSystemsCommunicationsServicesInc.Member_7DDEFA1927E4D6EEA08071BA97EAECCA" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_TelecommunicationsSpecialtyConstructionContractorCanadaMember" xlink:label="loc_dy_TelecommunicationsSpecialtyConstructionContractorCanadaMember_B1D3F695CCC2DC596E8871AFD63CFF22" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_70DFCE520263E1FFBF2871AFD63CD696" xlink:to="loc_dy_TelecommunicationsSpecialtyConstructionContractorCanadaMember_B1D3F695CCC2DC596E8871AFD63CFF22" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_WattsBrothersCableConstructionInc.Member" xlink:label="loc_dy_WattsBrothersCableConstructionInc.Member_F47E5AF48203E07DB51871AFD63D6905" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_70DFCE520263E1FFBF2871AFD63CD696" xlink:to="loc_dy_WattsBrothersCableConstructionInc.Member_F47E5AF48203E07DB51871AFD63D6905" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_46A95F11874786A4FB7A71AFD63DF06F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E727A8D84F807EECF2471AFD63DAF7C" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_46A95F11874786A4FB7A71AFD63DF06F" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_BusinessAcquisitionCostOfAcquiredEntityCashPaidForWorkingCapital" xlink:label="loc_dy_BusinessAcquisitionCostOfAcquiredEntityCashPaidForWorkingCapital_2E9C5EF256B067E3DFE671AFD63DCF6B" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E727A8D84F807EECF2471AFD63DAF7C" xlink:to="loc_dy_BusinessAcquisitionCostOfAcquiredEntityCashPaidForWorkingCapital_2E9C5EF256B067E3DFE671AFD63DCF6B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_E98CA0170190272C232A71AFD63D5938" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E727A8D84F807EECF2471AFD63DAF7C" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_E98CA0170190272C232A71AFD63D5938" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NumberOfBusinessesAcquired" xlink:label="loc_us-gaap_NumberOfBusinessesAcquired_D251E5346870C82C057771BBBEF86FFE" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E727A8D84F807EECF2471AFD63DAF7C" xlink:to="loc_us-gaap_NumberOfBusinessesAcquired_D251E5346870C82C057771BBBEF86FFE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_E98AC31C07987033DAEC71AFD63D60E7" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E727A8D84F807EECF2471AFD63DAF7C" xlink:to="loc_us-gaap_Goodwill_E98AC31C07987033DAEC71AFD63D60E7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedCustomerRelationshipsGross" xlink:label="loc_us-gaap_FiniteLivedCustomerRelationshipsGross_DFCF65FECAF7E7CBD30B71AFD63DA65E" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E727A8D84F807EECF2471AFD63DAF7C" xlink:to="loc_us-gaap_FiniteLivedCustomerRelationshipsGross_DFCF65FECAF7E7CBD30B71AFD63DA65E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_040DB7BC8B67CF9CBA4F71AFD63D34FA" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9E727A8D84F807EECF2471AFD63DAF7C" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_040DB7BC8B67CF9CBA4F71AFD63D34FA" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/BasisOfPresentationAndAccountingPolicies" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/BasisOfPresentationAndAccountingPoliciesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_F37096FFDEF8AFACD3C378A063371B1B" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_F7ECF20E5082D14DE13178A06335C30D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_F37096FFDEF8AFACD3C378A063371B1B" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_F7ECF20E5082D14DE13178A06335C30D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementGeographicalAxis" xlink:label="loc_us-gaap_StatementGeographicalAxis_2474D04BBF5B07B6A52C78A0633664E4" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_F7ECF20E5082D14DE13178A06335C30D" xlink:to="loc_us-gaap_StatementGeographicalAxis_2474D04BBF5B07B6A52C78A0633664E4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="loc_us-gaap_SegmentGeographicalDomain_3D4AADBBE3F232DE9DEB78A063368E9D_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementGeographicalAxis_2474D04BBF5B07B6A52C78A0633664E4" xlink:to="loc_us-gaap_SegmentGeographicalDomain_3D4AADBBE3F232DE9DEB78A063368E9D_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="loc_us-gaap_SegmentGeographicalDomain_3D4AADBBE3F232DE9DEB78A063368E9D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementGeographicalAxis_2474D04BBF5B07B6A52C78A0633664E4" xlink:to="loc_us-gaap_SegmentGeographicalDomain_3D4AADBBE3F232DE9DEB78A063368E9D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/country/2013/country-2013-01-31.xsd#country_CA" xlink:label="loc_country_CA_140F44F87B6D13534D2678A06336B260" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentGeographicalDomain_3D4AADBBE3F232DE9DEB78A063368E9D" xlink:to="loc_country_CA_140F44F87B6D13534D2678A06336B260" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_CB2BD1F32CB167FEDA7078A06336C238" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_F7ECF20E5082D14DE13178A06335C30D" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_CB2BD1F32CB167FEDA7078A06336C238" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_8E621C48A8477C2A8FE778A063373451_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_CB2BD1F32CB167FEDA7078A06336C238" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_8E621C48A8477C2A8FE778A063373451_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_8E621C48A8477C2A8FE778A063373451" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_CB2BD1F32CB167FEDA7078A06336C238" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_8E621C48A8477C2A8FE778A063373451" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SeniorSubordinatedNotesMember" xlink:label="loc_us-gaap_SeniorSubordinatedNotesMember_505B11FE2D32A97BD2D178A063371CCC" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_8E621C48A8477C2A8FE778A063373451" xlink:to="loc_us-gaap_SeniorSubordinatedNotesMember_505B11FE2D32A97BD2D178A063371CCC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_AD83EAE6C2457237580878A063371CBF" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_F7ECF20E5082D14DE13178A06335C30D" xlink:to="loc_us-gaap_DebtInstrumentAxis_AD83EAE6C2457237580878A063371CBF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_FF94CD0AC41CF94E6DD178A06337BFE0_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_AD83EAE6C2457237580878A063371CBF" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_FF94CD0AC41CF94E6DD178A06337BFE0_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_FF94CD0AC41CF94E6DD178A06337BFE0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_AD83EAE6C2457237580878A063371CBF" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_FF94CD0AC41CF94E6DD178A06337BFE0" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member" xlink:label="loc_dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member_FD80F94C51DB154E6F7578A0633745F2" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_FF94CD0AC41CF94E6DD178A06337BFE0" xlink:to="loc_dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member_FD80F94C51DB154E6F7578A0633745F2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NumberOfReportableSegments" xlink:label="loc_us-gaap_NumberOfReportableSegments_AC6049A3269D38C1949978A06337A60C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_F37096FFDEF8AFACD3C378A063371B1B" xlink:to="loc_us-gaap_NumberOfReportableSegments_AC6049A3269D38C1949978A06337A60C" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_NumberofSubsidiaries" xlink:label="loc_dy_NumberofSubsidiaries_C28E8727135C6B8F6ECB78A063374735" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_F37096FFDEF8AFACD3C378A063371B1B" xlink:to="loc_dy_NumberofSubsidiaries_C28E8727135C6B8F6ECB78A063374735" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SalesRevenueServicesNet" xlink:label="loc_us-gaap_SalesRevenueServicesNet_BC2F109DE1C67C1A74ED78A063376DA6" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_F37096FFDEF8AFACD3C378A063371B1B" xlink:to="loc_us-gaap_SalesRevenueServicesNet_BC2F109DE1C67C1A74ED78A063376DA6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_06373ADBA05E6C20C85C78A06337B742" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_F37096FFDEF8AFACD3C378A063371B1B" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_06373ADBA05E6C20C85C78A06337B742" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_B8A73090E47B59F426E178A06337C54C" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_F37096FFDEF8AFACD3C378A063371B1B" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_B8A73090E47B59F426E178A06337C54C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InvestmentsAndOtherNoncurrentAssets" xlink:label="loc_us-gaap_InvestmentsAndOtherNoncurrentAssets_82E96F900C7D63BF54C678A201E452E4" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_F37096FFDEF8AFACD3C378A063371B1B" xlink:to="loc_us-gaap_InvestmentsAndOtherNoncurrentAssets_82E96F900C7D63BF54C678A201E452E4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockDividendRatePercentage" xlink:label="loc_us-gaap_PreferredStockDividendRatePercentage_86544CD20F94908A49C278A0633772EC" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_F37096FFDEF8AFACD3C378A063371B1B" xlink:to="loc_us-gaap_PreferredStockDividendRatePercentage_86544CD20F94908A49C278A0633772EC" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/BasisOfPresentationAndAccountingPoliciesPolicies" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/CapitalStock" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/CapitalStockDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:label="loc_us-gaap_ClassOfStockLineItems_8600178F680068BCF72368E5EFA7CCD7" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_D2928239B2FAE22B390268E5EFA68CC7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_8600178F680068BCF72368E5EFA7CCD7" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_D2928239B2FAE22B390268E5EFA68CC7" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_9C29280437CDD9C54F6E68E5EFA68DC6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_D2928239B2FAE22B390268E5EFA68CC7" xlink:to="loc_us-gaap_StatementClassOfStockAxis_9C29280437CDD9C54F6E68E5EFA68DC6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_AD2E03B50462E943B98B68E5EFA6106A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_9C29280437CDD9C54F6E68E5EFA68DC6" xlink:to="loc_us-gaap_ClassOfStockDomain_AD2E03B50462E943B98B68E5EFA6106A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_AD2E03B50462E943B98B68E5EFA6106A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_9C29280437CDD9C54F6E68E5EFA68DC6" xlink:to="loc_us-gaap_ClassOfStockDomain_AD2E03B50462E943B98B68E5EFA6106A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_2C6B3AAD79BD72DB248F68E5EFA7AA67" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_AD2E03B50462E943B98B68E5EFA6106A" xlink:to="loc_us-gaap_CommonStockMember_2C6B3AAD79BD72DB248F68E5EFA7AA67" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_8CC9CBB7C4F6F02FD71C68E5EFA767C4" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_8600178F680068BCF72368E5EFA7CCD7" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_8CC9CBB7C4F6F02FD71C68E5EFA767C4" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_AveragePricePerShareRepurchaseOfCommonStock" xlink:label="loc_dy_AveragePricePerShareRepurchaseOfCommonStock_7AB51CE72596C09B6C2F68E5EFA712E5" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_8600178F680068BCF72368E5EFA7CCD7" xlink:to="loc_dy_AveragePricePerShareRepurchaseOfCommonStock_7AB51CE72596C09B6C2F68E5EFA712E5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_E863CFD537103B73182268E5EFA721F0" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_8600178F680068BCF72368E5EFA7CCD7" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_E863CFD537103B73182268E5EFA721F0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_F56B2E860CE37C40707E68E5EFA7DF3F" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_8600178F680068BCF72368E5EFA7CCD7" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_F56B2E860CE37C40707E68E5EFA7DF3F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_87DD0F147004527760C568E5EFA72561" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_8600178F680068BCF72368E5EFA7CCD7" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_87DD0F147004527760C568E5EFA72561" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_56F701BE2F98ECEBFA8468E5EFA8D1BA" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_8600178F680068BCF72368E5EFA7CCD7" xlink:to="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_56F701BE2F98ECEBFA8468E5EFA8D1BA" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_ValueofSharesPaidforTaxWithholdingforShareBasedCompensation" xlink:label="loc_dy_ValueofSharesPaidforTaxWithholdingforShareBasedCompensation_5CE4AC51F106A6ABCC1768E5EFA832D8" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_8600178F680068BCF72368E5EFA7CCD7" xlink:to="loc_dy_ValueofSharesPaidforTaxWithholdingforShareBasedCompensation_5CE4AC51F106A6ABCC1768E5EFA832D8" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/CommitmentsAndContingencies" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/CommitmentsAndContingenciesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermPurchaseCommitmentLineItems" xlink:label="loc_us-gaap_LongTermPurchaseCommitmentLineItems_709E72768D0B30CD010676E45F1E945A" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_4F4D6469348DF380A17176E45F1DC745" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LongTermPurchaseCommitmentLineItems_709E72768D0B30CD010676E45F1E945A" xlink:to="loc_us-gaap_LossContingenciesTable_4F4D6469348DF380A17176E45F1DC745" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GuaranteeObligationsByNatureAxis" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis_ADDA891B5B4F1B54773676E45F1D0EB2" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_4F4D6469348DF380A17176E45F1DC745" xlink:to="loc_us-gaap_GuaranteeObligationsByNatureAxis_ADDA891B5B4F1B54773676E45F1D0EB2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GuaranteeObligationsNatureDomain" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_EBA829546E46C408B43776E45F1D79E4_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_ADDA891B5B4F1B54773676E45F1D0EB2" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_EBA829546E46C408B43776E45F1D79E4_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GuaranteeObligationsNatureDomain" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_EBA829546E46C408B43776E45F1D79E4" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_ADDA891B5B4F1B54773676E45F1D0EB2" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_EBA829546E46C408B43776E45F1D79E4" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_PerformanceGuaranteeAndSuretyBondMember" xlink:label="loc_dy_PerformanceGuaranteeAndSuretyBondMember_628B6E09871BFD2F865676E45F1D25F7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_EBA829546E46C408B43776E45F1D79E4" xlink:to="loc_dy_PerformanceGuaranteeAndSuretyBondMember_628B6E09871BFD2F865676E45F1D25F7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_2264F68F640B4D2EC80A76E45F1D3B97" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_4F4D6469348DF380A17176E45F1DC745" xlink:to="loc_us-gaap_DebtInstrumentAxis_2264F68F640B4D2EC80A76E45F1D3B97" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_CBD9F21344859F72EA7276E45F1D58D1_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_2264F68F640B4D2EC80A76E45F1D3B97" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_CBD9F21344859F72EA7276E45F1D58D1_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_CBD9F21344859F72EA7276E45F1D58D1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_2264F68F640B4D2EC80A76E45F1D3B97" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_CBD9F21344859F72EA7276E45F1D58D1" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_CreditAgreementDecember32012MaturingDecember2017Member" xlink:label="loc_dy_CreditAgreementDecember32012MaturingDecember2017Member_E10B678B12AE77758E1976E45F1D617D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_CBD9F21344859F72EA7276E45F1D58D1" xlink:to="loc_dy_CreditAgreementDecember32012MaturingDecember2017Member_E10B678B12AE77758E1976E45F1D617D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_D53A797F5D0F99A6816E76E45F1D4F1F" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_4F4D6469348DF380A17176E45F1DC745" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_D53A797F5D0F99A6816E76E45F1D4F1F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_E2180737F2D2C80FEEBE76E45F1DE155_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_D53A797F5D0F99A6816E76E45F1D4F1F" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_E2180737F2D2C80FEEBE76E45F1DE155_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_E2180737F2D2C80FEEBE76E45F1DE155" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_D53A797F5D0F99A6816E76E45F1D4F1F" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_E2180737F2D2C80FEEBE76E45F1DE155" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_5B283BD293E2C04F5D9976E45F1EBCAC" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_E2180737F2D2C80FEEBE76E45F1DE155" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_5B283BD293E2C04F5D9976E45F1EBCAC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_B61FB1C28952B57A8ED376E45F1EBE1C" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_4F4D6469348DF380A17176E45F1DC745" xlink:to="loc_us-gaap_CreditFacilityAxis_B61FB1C28952B57A8ED376E45F1EBE1C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_0F957727038D3CE3DF6576E45F1E0717_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_B61FB1C28952B57A8ED376E45F1EBE1C" xlink:to="loc_us-gaap_CreditFacilityDomain_0F957727038D3CE3DF6576E45F1E0717_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_0F957727038D3CE3DF6576E45F1E0717" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_B61FB1C28952B57A8ED376E45F1EBE1C" xlink:to="loc_us-gaap_CreditFacilityDomain_0F957727038D3CE3DF6576E45F1E0717" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StandbyLettersOfCreditMember" xlink:label="loc_us-gaap_StandbyLettersOfCreditMember_93F78E5185BADDBD4EE876E45F1E2420" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_0F957727038D3CE3DF6576E45F1E0717" xlink:to="loc_us-gaap_StandbyLettersOfCreditMember_93F78E5185BADDBD4EE876E45F1E2420" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LossContingencyDamagesSought" xlink:label="loc_us-gaap_LossContingencyDamagesSought_F5B1466A157FA35C849F76E45F1E38F3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermPurchaseCommitmentLineItems_709E72768D0B30CD010676E45F1E945A" xlink:to="loc_us-gaap_LossContingencyDamagesSought_F5B1466A157FA35C849F76E45F1E38F3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_B4BEA7C9F7DE1FD958AA76E45F1EED2F" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermPurchaseCommitmentLineItems_709E72768D0B30CD010676E45F1E945A" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_B4BEA7C9F7DE1FD958AA76E45F1EED2F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_B1BCDF2DC2AFDD63DEB676E45F1EE77F" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermPurchaseCommitmentLineItems_709E72768D0B30CD010676E45F1E945A" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_B1BCDF2DC2AFDD63DEB676E45F1EE77F" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/ComputationOfEarningsPerCommonShare" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/ComputationOfEarningsPerCommonShareDetails" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/ComputationOfEarningsPerCommonShareTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/ConcentrationOfCreditRisk" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/ConcentrationOfCreditRiskDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskLineItems" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_FBC1BA8A792C9AD5F8A076E45F2B58E0" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskTable" xlink:label="loc_us-gaap_ConcentrationRiskTable_D25A7C99F1FEABBDED1976E45F293A4D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_FBC1BA8A792C9AD5F8A076E45F2B58E0" xlink:to="loc_us-gaap_ConcentrationRiskTable_D25A7C99F1FEABBDED1976E45F293A4D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_CB45257BE8499E93976B76E45F2925A6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_D25A7C99F1FEABBDED1976E45F293A4D" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_CB45257BE8499E93976B76E45F2925A6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_AA856343B215A89C0CE976E45F29AA8B_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_CB45257BE8499E93976B76E45F2925A6" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_AA856343B215A89C0CE976E45F29AA8B_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_AA856343B215A89C0CE976E45F29AA8B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_CB45257BE8499E93976B76E45F2925A6" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_AA856343B215A89C0CE976E45F29AA8B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SalesRevenueServicesNetMember" xlink:label="loc_us-gaap_SalesRevenueServicesNetMember_2AC05D15A924DEE563C176E45F29D8E7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_AA856343B215A89C0CE976E45F29AA8B" xlink:to="loc_us-gaap_SalesRevenueServicesNetMember_2AC05D15A924DEE563C176E45F29D8E7" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_TradeAccountsReceivableandCostsandEstimatedEarningsMember" xlink:label="loc_dy_TradeAccountsReceivableandCostsandEstimatedEarningsMember_D85AEBED6413313F78F576E45F29BD40" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_AA856343B215A89C0CE976E45F29AA8B" xlink:to="loc_dy_TradeAccountsReceivableandCostsandEstimatedEarningsMember_D85AEBED6413313F78F576E45F29BD40" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_69D70740DA45434E62E376E45F2A4F98" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_D25A7C99F1FEABBDED1976E45F293A4D" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_69D70740DA45434E62E376E45F2A4F98" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_B18D9F0B824B491E6D8376E45F2A3D7F_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_69D70740DA45434E62E376E45F2A4F98" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_B18D9F0B824B491E6D8376E45F2A3D7F_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_B18D9F0B824B491E6D8376E45F2A3D7F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_69D70740DA45434E62E376E45F2A4F98" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_B18D9F0B824B491E6D8376E45F2A3D7F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_D8D26B93D5C52F973D3E76E45F2A3F5B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_B18D9F0B824B491E6D8376E45F2A3D7F" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_D8D26B93D5C52F973D3E76E45F2A3F5B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MajorCustomersAxis" xlink:label="loc_us-gaap_MajorCustomersAxis_7C5B4056C52E555042DF76E45F2A33DA" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_D25A7C99F1FEABBDED1976E45F293A4D" xlink:to="loc_us-gaap_MajorCustomersAxis_7C5B4056C52E555042DF76E45F2A33DA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NameOfMajorCustomerDomain" xlink:label="loc_us-gaap_NameOfMajorCustomerDomain_722B11DF7F56815733B876E45F2A0480_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MajorCustomersAxis_7C5B4056C52E555042DF76E45F2A33DA" xlink:to="loc_us-gaap_NameOfMajorCustomerDomain_722B11DF7F56815733B876E45F2A0480_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NameOfMajorCustomerDomain" xlink:label="loc_us-gaap_NameOfMajorCustomerDomain_722B11DF7F56815733B876E45F2A0480" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MajorCustomersAxis_7C5B4056C52E555042DF76E45F2A33DA" xlink:to="loc_us-gaap_NameOfMajorCustomerDomain_722B11DF7F56815733B876E45F2A0480" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_FiveUnnamedCustomersMember" xlink:label="loc_dy_FiveUnnamedCustomersMember_F0612581FF736DB2D97876E45F2A9B2A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NameOfMajorCustomerDomain_722B11DF7F56815733B876E45F2A0480" xlink:to="loc_dy_FiveUnnamedCustomersMember_F0612581FF736DB2D97876E45F2A9B2A" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_AttMember" xlink:label="loc_dy_AttMember_7B204C4ADD69EB26F5C276E45F2AA550" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NameOfMajorCustomerDomain_722B11DF7F56815733B876E45F2A0480" xlink:to="loc_dy_AttMember_7B204C4ADD69EB26F5C276E45F2AA550" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_CenturylinkMember" xlink:label="loc_dy_CenturylinkMember_9EAABB9A87ED5DCF622B76E45F2A4779" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NameOfMajorCustomerDomain_722B11DF7F56815733B876E45F2A0480" xlink:to="loc_dy_CenturylinkMember_9EAABB9A87ED5DCF622B76E45F2A4779" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_ComcastMember" xlink:label="loc_dy_ComcastMember_184DB855CB878E28E51276E45F2AF2AD" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NameOfMajorCustomerDomain_722B11DF7F56815733B876E45F2A0480" xlink:to="loc_dy_ComcastMember_184DB855CB878E28E51276E45F2AF2AD" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_CustomerAMember" xlink:label="loc_dy_CustomerAMember_61EF44933FD3D94835BF76E9EC2BA6A1" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NameOfMajorCustomerDomain_722B11DF7F56815733B876E45F2A0480" xlink:to="loc_dy_CustomerAMember_61EF44933FD3D94835BF76E9EC2BA6A1" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_NumberOfCustomersClassifiedAsHighlyConcentrated" xlink:label="loc_dy_NumberOfCustomersClassifiedAsHighlyConcentrated_C8A525B93D4BEBBC37E776E45F2B3165" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_FBC1BA8A792C9AD5F8A076E45F2B58E0" xlink:to="loc_dy_NumberOfCustomersClassifiedAsHighlyConcentrated_C8A525B93D4BEBBC37E776E45F2B3165" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_C60F54A58839E143073476E45F2BF4C1" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_FBC1BA8A792C9AD5F8A076E45F2B58E0" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_C60F54A58839E143073476E45F2BF4C1" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_ConcentrationRiskAmount" xlink:label="loc_dy_ConcentrationRiskAmount_28202809FB757A8C105F76E45F2B46CF" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_FBC1BA8A792C9AD5F8A076E45F2B58E0" xlink:to="loc_dy_ConcentrationRiskAmount_28202809FB757A8C105F76E45F2B46CF" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/ConcentrationOfCreditRiskTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/ConsolidatedBalanceSheets" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/ConsolidatedStatementsOfOperations" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/ConsolidatedStatementsOfOperationsParenthetical" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/CostsAndEstimatedEarningsInExcessOfBillings" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/CostsAndEstimatedEarningsInExcessOfBillingsDetails" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/CostsAndEstimatedEarningsInExcessOfBillingsTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/Debt" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/DebtDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_1B5B6827A73F5A0A4656791395B8C8F8" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_DebtInstrumentTable_1B5B6827A73F5A0A4656791395B8C8F8" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_C67BE2098DF984380CA0791395B843D6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1B5B6827A73F5A0A4656791395B8C8F8" xlink:to="loc_us-gaap_RangeAxis_C67BE2098DF984380CA0791395B843D6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_1F7F567223790EB77667791395B81111_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_C67BE2098DF984380CA0791395B843D6" xlink:to="loc_us-gaap_RangeMember_1F7F567223790EB77667791395B81111_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_1F7F567223790EB77667791395B81111" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_C67BE2098DF984380CA0791395B843D6" xlink:to="loc_us-gaap_RangeMember_1F7F567223790EB77667791395B81111" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_EFEAE0BD66B62674D5AD791395B8BD43" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_1F7F567223790EB77667791395B81111" xlink:to="loc_us-gaap_MinimumMember_EFEAE0BD66B62674D5AD791395B8BD43" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_49EA4700E8F2533FB711791395B86108" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_1F7F567223790EB77667791395B81111" xlink:to="loc_us-gaap_MaximumMember_49EA4700E8F2533FB711791395B86108" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_D68FB4409247BB3E1CC7791395B876C7" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1B5B6827A73F5A0A4656791395B8C8F8" xlink:to="loc_us-gaap_VariableRateAxis_D68FB4409247BB3E1CC7791395B876C7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_F04AE1CBCFA69C09C49D791395B8787F_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_D68FB4409247BB3E1CC7791395B876C7" xlink:to="loc_us-gaap_VariableRateDomain_F04AE1CBCFA69C09C49D791395B8787F_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_F04AE1CBCFA69C09C49D791395B8787F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_D68FB4409247BB3E1CC7791395B876C7" xlink:to="loc_us-gaap_VariableRateDomain_F04AE1CBCFA69C09C49D791395B8787F" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_FederalFundRateMember" xlink:label="loc_dy_FederalFundRateMember_E765C2AD3024C4C0F69B791395B90042" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_F04AE1CBCFA69C09C49D791395B8787F" xlink:to="loc_dy_FederalFundRateMember_E765C2AD3024C4C0F69B791395B90042" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_86080AC91A371201C96D791395B9BA5E" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_F04AE1CBCFA69C09C49D791395B8787F" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_86080AC91A371201C96D791395B9BA5E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EurodollarMember" xlink:label="loc_us-gaap_EurodollarMember_82696EE52B6597D47FA0791395B94E4D" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_F04AE1CBCFA69C09C49D791395B8787F" xlink:to="loc_us-gaap_EurodollarMember_82696EE52B6597D47FA0791395B94E4D" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_AdministrativeAgentBaseRateMember" xlink:label="loc_dy_AdministrativeAgentBaseRateMember_619A41DA8F218A68FC61791395B9425D" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_F04AE1CBCFA69C09C49D791395B8787F" xlink:to="loc_dy_AdministrativeAgentBaseRateMember_619A41DA8F218A68FC61791395B9425D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_4C2BFC16ED6BB7B8E188791395B98DC2" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1B5B6827A73F5A0A4656791395B8C8F8" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_4C2BFC16ED6BB7B8E188791395B98DC2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_FB922DBD079AA5564105791395B94F0A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_4C2BFC16ED6BB7B8E188791395B98DC2" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_FB922DBD079AA5564105791395B94F0A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_FB922DBD079AA5564105791395B94F0A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_4C2BFC16ED6BB7B8E188791395B98DC2" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_FB922DBD079AA5564105791395B94F0A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SeniorSubordinatedNotesMember" xlink:label="loc_us-gaap_SeniorSubordinatedNotesMember_A315BBC114E35C247EAA791395B9B459" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_FB922DBD079AA5564105791395B94F0A" xlink:to="loc_us-gaap_SeniorSubordinatedNotesMember_A315BBC114E35C247EAA791395B9B459" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SeniorLoansMember" xlink:label="loc_us-gaap_SeniorLoansMember_5921DB2B9E02429AF95B791395B90B20" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_FB922DBD079AA5564105791395B94F0A" xlink:to="loc_us-gaap_SeniorLoansMember_5921DB2B9E02429AF95B791395B90B20" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StandbyLettersOfCreditMember" xlink:label="loc_us-gaap_StandbyLettersOfCreditMember_B6EDAC2F70DCFF2642FF791395B93894" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_FB922DBD079AA5564105791395B94F0A" xlink:to="loc_us-gaap_StandbyLettersOfCreditMember_B6EDAC2F70DCFF2642FF791395B93894" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_C6CB382C116AC40A6489791395B9D5D2" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_FB922DBD079AA5564105791395B94F0A" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_C6CB382C116AC40A6489791395B9D5D2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_AB2CF7C79D3A18D9D5EF791395B9AAA1" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1B5B6827A73F5A0A4656791395B8C8F8" xlink:to="loc_us-gaap_DebtInstrumentAxis_AB2CF7C79D3A18D9D5EF791395B9AAA1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_778858B6D1A112B56EEF791395B9AC54_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_AB2CF7C79D3A18D9D5EF791395B9AAA1" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_778858B6D1A112B56EEF791395B9AC54_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_778858B6D1A112B56EEF791395B9AC54" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_AB2CF7C79D3A18D9D5EF791395B9AAA1" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_778858B6D1A112B56EEF791395B9AC54" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member" xlink:label="loc_dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member_83D4F55BD14A53F3EDC4791395BAF1A2" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_778858B6D1A112B56EEF791395B9AC54" xlink:to="loc_dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member_83D4F55BD14A53F3EDC4791395BAF1A2" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_CreditAgreementDecember32012MaturingDecember2017Member" xlink:label="loc_dy_CreditAgreementDecember32012MaturingDecember2017Member_12D65FDFCC7FB550491C791395BACEE0" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_778858B6D1A112B56EEF791395B9AC54" xlink:to="loc_dy_CreditAgreementDecember32012MaturingDecember2017Member_12D65FDFCC7FB550491C791395BACEE0" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_CreditAgreementMember" xlink:label="loc_dy_CreditAgreementMember_EF3B395582B1D8D3E0087915CC72C91C" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_778858B6D1A112B56EEF791395B9AC54" xlink:to="loc_dy_CreditAgreementMember_EF3B395582B1D8D3E0087915CC72C91C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_091CDF5220476EAF2459791395BA6B0D" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1B5B6827A73F5A0A4656791395B8C8F8" xlink:to="loc_us-gaap_CreditFacilityAxis_091CDF5220476EAF2459791395BA6B0D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_E90529AEBC85969DFF63791395BAF3FC_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_091CDF5220476EAF2459791395BA6B0D" xlink:to="loc_us-gaap_CreditFacilityDomain_E90529AEBC85969DFF63791395BAF3FC_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_E90529AEBC85969DFF63791395BAF3FC" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_091CDF5220476EAF2459791395BA6B0D" xlink:to="loc_us-gaap_CreditFacilityDomain_E90529AEBC85969DFF63791395BAF3FC" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_SwinglineLoansMember" xlink:label="loc_dy_SwinglineLoansMember_DA870EA66A2EAE42B13E791395BAB045" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_E90529AEBC85969DFF63791395BAF3FC" xlink:to="loc_dy_SwinglineLoansMember_DA870EA66A2EAE42B13E791395BAB045" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_CommercialLettersofCreditMember" xlink:label="loc_dy_CommercialLettersofCreditMember_6FFAFFB8D90352348056791395BABC99" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_E90529AEBC85969DFF63791395BAF3FC" xlink:to="loc_dy_CommercialLettersofCreditMember_6FFAFFB8D90352348056791395BABC99" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StandbyLettersOfCreditMember" xlink:label="loc_us-gaap_StandbyLettersOfCreditMember_AD1C20A96273276962C3791395BBB0A6" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_E90529AEBC85969DFF63791395BAF3FC" xlink:to="loc_us-gaap_StandbyLettersOfCreditMember_AD1C20A96273276962C3791395BBB0A6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_9BEA02AFAAF0FCD1B16C791395BB413E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_9BEA02AFAAF0FCD1B16C791395BB413E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtAndCapitalLeaseObligations" xlink:label="loc_us-gaap_DebtAndCapitalLeaseObligations_26A8CCC795D1F040B654791395BB4485" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_DebtAndCapitalLeaseObligations_26A8CCC795D1F040B654791395BB4485" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_DF64EFE6E8E0B2ED73BD791395BB0648" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_DF64EFE6E8E0B2ED73BD791395BB0648" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentUnamortizedPremium" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedPremium_5BF69E19C0DB8805F8F0791395BB0BFD" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedPremium_5BF69E19C0DB8805F8F0791395BB0BFD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtFairValue" xlink:label="loc_us-gaap_LongTermDebtFairValue_16C37B6C8F1B18408D04791395BB6129" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_LongTermDebtFairValue_16C37B6C8F1B18408D04791395BB6129" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_E5B0B54FD8B502F94C11791395BB0E1D" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_E5B0B54FD8B502F94C11791395BB0E1D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_5FDD5E57D9CEC5A86892791395BBA504" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_5FDD5E57D9CEC5A86892791395BBA504" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_A191A487E35000F35FC9791395BB59BF" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_A191A487E35000F35FC9791395BB59BF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_52736747559F9F14ACC7791395BB16DE" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_52736747559F9F14ACC7791395BB16DE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_39EE9CAFD6EC44999499791395BB73CD" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_39EE9CAFD6EC44999499791395BB73CD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_27419EEAF8A1E7D8D1F3791395BBB5EA" xlink:type="locator" />
    <definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_27419EEAF8A1E7D8D1F3791395BBB5EA" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_LineofCreditFacilityIncrementalAdditionalFacilitiesOptionAmount" xlink:label="loc_dy_LineofCreditFacilityIncrementalAdditionalFacilitiesOptionAmount_6693D1EA71B8D1F40DD6791395BC362D" xlink:type="locator" />
    <definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_dy_LineofCreditFacilityIncrementalAdditionalFacilitiesOptionAmount_6693D1EA71B8D1F40DD6791395BC362D" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_DebtInstrumentCovenantComplianceConsolidatedLeverageRatioMaximum" xlink:label="loc_dy_DebtInstrumentCovenantComplianceConsolidatedLeverageRatioMaximum_D552A5F9CB2ACEB43694791395BC51FE" xlink:type="locator" />
    <definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FE196343F709C573FDE4791395BB626C" xlink:to="loc_dy_DebtInstrumentCovenantComplianceConsolidatedLeverageRatioMaximum_D552A5F9CB2ACEB43694791395BC51FE" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/DebtOutstandingDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_9A6CFD42D26D75FF96AA791395C3267A" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_F56747A054107D52F073791395C1D671" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9A6CFD42D26D75FF96AA791395C3267A" xlink:to="loc_us-gaap_DebtInstrumentTable_F56747A054107D52F073791395C1D671" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_61D741D6F9E6AEACB183791395C239F5" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_F56747A054107D52F073791395C1D671" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_61D741D6F9E6AEACB183791395C239F5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_EBF7E5E26D3143E50A32791395C2C7A1_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_61D741D6F9E6AEACB183791395C239F5" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_EBF7E5E26D3143E50A32791395C2C7A1_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_EBF7E5E26D3143E50A32791395C2C7A1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_61D741D6F9E6AEACB183791395C239F5" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_EBF7E5E26D3143E50A32791395C2C7A1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_41D5CB5416BF6AFB0EC6791395C27007" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_EBF7E5E26D3143E50A32791395C2C7A1" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_41D5CB5416BF6AFB0EC6791395C27007" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SeniorLoansMember" xlink:label="loc_us-gaap_SeniorLoansMember_B6A065F9E1788998851E791395C2147C" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_EBF7E5E26D3143E50A32791395C2C7A1" xlink:to="loc_us-gaap_SeniorLoansMember_B6A065F9E1788998851E791395C2147C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SeniorSubordinatedNotesMember" xlink:label="loc_us-gaap_SeniorSubordinatedNotesMember_C3EE06990B1EC19954F6791395C294B5" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_EBF7E5E26D3143E50A32791395C2C7A1" xlink:to="loc_us-gaap_SeniorSubordinatedNotesMember_C3EE06990B1EC19954F6791395C294B5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_FB32EFF55691883B4671791395C2BDFA" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_F56747A054107D52F073791395C1D671" xlink:to="loc_us-gaap_DebtInstrumentAxis_FB32EFF55691883B4671791395C2BDFA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_FE0F29F9ECE0537074A7791395C29AA5_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_FB32EFF55691883B4671791395C2BDFA" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_FE0F29F9ECE0537074A7791395C29AA5_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_FE0F29F9ECE0537074A7791395C29AA5" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_FB32EFF55691883B4671791395C2BDFA" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_FE0F29F9ECE0537074A7791395C29AA5" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_CreditAgreementMember" xlink:label="loc_dy_CreditAgreementMember_42298AB455E5D2E5D86279149D99DC88" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_FE0F29F9ECE0537074A7791395C29AA5" xlink:to="loc_dy_CreditAgreementMember_42298AB455E5D2E5D86279149D99DC88" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member" xlink:label="loc_dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member_3535B54BFE522D50AFB8791395C39B04" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_FE0F29F9ECE0537074A7791395C29AA5" xlink:to="loc_dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member_3535B54BFE522D50AFB8791395C39B04" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_F72B8D3D6FFF1BBC0C56791395C3A5A7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9A6CFD42D26D75FF96AA791395C3267A" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_F72B8D3D6FFF1BBC0C56791395C3A5A7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtAndCapitalLeaseObligations" xlink:label="loc_us-gaap_DebtAndCapitalLeaseObligations_64186D2B00223290C24C791395C38ED4" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9A6CFD42D26D75FF96AA791395C3267A" xlink:to="loc_us-gaap_DebtAndCapitalLeaseObligations_64186D2B00223290C24C791395C38ED4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentUnamortizedPremium" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedPremium_CF58CCE60F9DA84B25C6791395C3A667" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9A6CFD42D26D75FF96AA791395C3267A" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedPremium_CF58CCE60F9DA84B25C6791395C3A667" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_7862BD0AE6D23AA6E1C2791395C3FF14" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9A6CFD42D26D75FF96AA791395C3267A" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_7862BD0AE6D23AA6E1C2791395C3FF14" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_F23075BD2998F020A0B0791395C3F460" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9A6CFD42D26D75FF96AA791395C3267A" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_F23075BD2998F020A0B0791395C3F460" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/DebtTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/DocumentAndEntityInformation" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/GoodwillAndIntangibleAssets" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/GoodwillAndIntangibleAssetsChangesInCarryingAmountOfGoodwillDetails" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/GoodwillAndIntangibleAssetsDetails" xlink:type="extended">
    <loc xlink:href="dy-20150425.xsd#dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:label="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_35FC7D10D1E057ADD3C071AFD607D0AC" xlink:type="locator" />
    <loc xlink:href="dy-20150425.xsd#dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" xlink:label="loc_dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_6DC80D3A77E80416B9ED71AFD6050AFA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_35FC7D10D1E057ADD3C071AFD607D0AC" xlink:to="loc_dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_6DC80D3A77E80416B9ED71AFD6050AFA" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_10013F787DB2A4DD279B71AFD605D828" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_6DC80D3A77E80416B9ED71AFD6050AFA" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_10013F787DB2A4DD279B71AFD605D828" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_8983C3A185E6180FA34871AFD60526F7_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_10013F787DB2A4DD279B71AFD605D828" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_8983C3A185E6180FA34871AFD60526F7_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_8983C3A185E6180FA34871AFD60526F7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_10013F787DB2A4DD279B71AFD605D828" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_8983C3A185E6180FA34871AFD60526F7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_83E539A7E3198928CD7D71AFD605B718" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_8983C3A185E6180FA34871AFD60526F7" xlink:to="loc_us-gaap_CustomerRelationshipsMember_83E539A7E3198928CD7D71AFD605B718" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OrderOrProductionBacklogMember" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_C0E5595116CE9F5C3F1771AFD606C6F2" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_8983C3A185E6180FA34871AFD60526F7" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_C0E5595116CE9F5C3F1771AFD606C6F2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_BE6E03BAFAEC7E9C0BC171AFD606BE74" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_6DC80D3A77E80416B9ED71AFD6050AFA" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_BE6E03BAFAEC7E9C0BC171AFD606BE74" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3CFE8441F31B3560A15571AFD606F123_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_BE6E03BAFAEC7E9C0BC171AFD606BE74" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3CFE8441F31B3560A15571AFD606F123_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3CFE8441F31B3560A15571AFD606F123" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_BE6E03BAFAEC7E9C0BC171AFD606BE74" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3CFE8441F31B3560A15571AFD606F123" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_BusinessesAcquiredinFiscal2013Member" xlink:label="loc_dy_BusinessesAcquiredinFiscal2013Member_B756DE8CB9789884171871AFD6064049" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3CFE8441F31B3560A15571AFD606F123" xlink:to="loc_dy_BusinessesAcquiredinFiscal2013Member_B756DE8CB9789884171871AFD6064049" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_BusinessOneAcquiredinFiscal2013Member" xlink:label="loc_dy_BusinessOneAcquiredinFiscal2013Member_E73E18F0A52C5B4FA06171AFD606B716" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3CFE8441F31B3560A15571AFD606F123" xlink:to="loc_dy_BusinessOneAcquiredinFiscal2013Member_E73E18F0A52C5B4FA06171AFD606B716" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_BusinessTwoAcquiredinFiscal2013Member" xlink:label="loc_dy_BusinessTwoAcquiredinFiscal2013Member_329B5BF6DE286E222FF371AFD606FDF8" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3CFE8441F31B3560A15571AFD606F123" xlink:to="loc_dy_BusinessTwoAcquiredinFiscal2013Member_329B5BF6DE286E222FF371AFD606FDF8" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_BusinessThreeAcquiredinFiscal2013Member" xlink:label="loc_dy_BusinessThreeAcquiredinFiscal2013Member_A601A94A8D76B89F584371AFD6060F26" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3CFE8441F31B3560A15571AFD606F123" xlink:to="loc_dy_BusinessThreeAcquiredinFiscal2013Member_A601A94A8D76B89F584371AFD6060F26" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_HewittPowerCommunicationsIncMember" xlink:label="loc_dy_HewittPowerCommunicationsIncMember_5906B5B083312A36747A71AFD607EC57" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3CFE8441F31B3560A15571AFD606F123" xlink:to="loc_dy_HewittPowerCommunicationsIncMember_5906B5B083312A36747A71AFD607EC57" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_97D3934C32CC72F064FB71AFD607AE7B" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_6DC80D3A77E80416B9ED71AFD6050AFA" xlink:to="loc_us-gaap_RangeAxis_97D3934C32CC72F064FB71AFD607AE7B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_981677CB9A1983D074FF71AFD607009E_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_97D3934C32CC72F064FB71AFD607AE7B" xlink:to="loc_us-gaap_RangeMember_981677CB9A1983D074FF71AFD607009E_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_981677CB9A1983D074FF71AFD607009E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_97D3934C32CC72F064FB71AFD607AE7B" xlink:to="loc_us-gaap_RangeMember_981677CB9A1983D074FF71AFD607009E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_FAA3E32573A0904C466E71AFD607D5EB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_981677CB9A1983D074FF71AFD607009E" xlink:to="loc_us-gaap_MinimumMember_FAA3E32573A0904C466E71AFD607D5EB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_D337A26E6910DBC4391671AFD607C3E2" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_981677CB9A1983D074FF71AFD607009E" xlink:to="loc_us-gaap_MaximumMember_D337A26E6910DBC4391671AFD607C3E2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_51F3B34C27AB0493C84571AFD607FAE1" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_6DC80D3A77E80416B9ED71AFD6050AFA" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_51F3B34C27AB0493C84571AFD607FAE1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_B62652A691D8D1502A8571AFD6075C4A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_51F3B34C27AB0493C84571AFD607FAE1" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_B62652A691D8D1502A8571AFD6075C4A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_B62652A691D8D1502A8571AFD6075C4A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_51F3B34C27AB0493C84571AFD607FAE1" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_B62652A691D8D1502A8571AFD6075C4A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GoodwillMember" xlink:label="loc_us-gaap_GoodwillMember_2CA7407A25AD9F69874571AFD607B7D5" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_B62652A691D8D1502A8571AFD6075C4A" xlink:to="loc_us-gaap_GoodwillMember_2CA7407A25AD9F69874571AFD607B7D5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_C50C72A7E1F83C17DE6871AFD607AA92" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_35FC7D10D1E057ADD3C071AFD607D0AC" xlink:to="loc_us-gaap_Goodwill_C50C72A7E1F83C17DE6871AFD607AA92" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_FairValueAssumptionsQualitativeAssessmentsAssetPercent" xlink:label="loc_dy_FairValueAssumptionsQualitativeAssessmentsAssetPercent_2BAD3B56F9BAB6DE40C471AFD60860FE" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_35FC7D10D1E057ADD3C071AFD607D0AC" xlink:to="loc_dy_FairValueAssumptionsQualitativeAssessmentsAssetPercent_2BAD3B56F9BAB6DE40C471AFD60860FE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueInputsDiscountRate" xlink:label="loc_us-gaap_FairValueInputsDiscountRate_59E843D9E03A3B85325071AFD608F8C5" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_35FC7D10D1E057ADD3C071AFD607D0AC" xlink:to="loc_us-gaap_FairValueInputsDiscountRate_59E843D9E03A3B85325071AFD608F8C5" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_FairValueAssumptionsTerminalGrowthRate" xlink:label="loc_dy_FairValueAssumptionsTerminalGrowthRate_43C13C87D6AD3C4A319B71AFD608EEA2" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_35FC7D10D1E057ADD3C071AFD607D0AC" xlink:to="loc_dy_FairValueAssumptionsTerminalGrowthRate_43C13C87D6AD3C4A319B71AFD608EEA2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssumptionsExpectedTerm" xlink:label="loc_us-gaap_FairValueAssumptionsExpectedTerm_1FC111E6CF6195418E2171AFD6082344" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_35FC7D10D1E057ADD3C071AFD607D0AC" xlink:to="loc_us-gaap_FairValueAssumptionsExpectedTerm_1FC111E6CF6195418E2171AFD6082344" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_NumberofReportingUnitsthatExceededCarryingValue" xlink:label="loc_dy_NumberofReportingUnitsthatExceededCarryingValue_2D75E22027C78065842671AFD6084D6F" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_35FC7D10D1E057ADD3C071AFD607D0AC" xlink:to="loc_dy_NumberofReportingUnitsthatExceededCarryingValue_2D75E22027C78065842671AFD6084D6F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount" xlink:label="loc_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount_8E749387BBFCE0CA07C271AFD608ED19" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_35FC7D10D1E057ADD3C071AFD607D0AC" xlink:to="loc_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount_8E749387BBFCE0CA07C271AFD608ED19" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_A743694E1BD092C5328271AFD6081F44" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_35FC7D10D1E057ADD3C071AFD607D0AC" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_A743694E1BD092C5328271AFD6081F44" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_D43103C61069C9D6614471AFD608C736" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_35FC7D10D1E057ADD3C071AFD607D0AC" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_D43103C61069C9D6614471AFD608C736" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/GoodwillAndIntangibleAssetsFutureAmortizationExpenseDetails" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/GoodwillAndIntangibleAssetsIntangibleAssetsDetails" xlink:type="extended">
    <loc xlink:href="dy-20150425.xsd#dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:label="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_3BFA817D86FD555E98EF700C4656442C" xlink:type="locator" />
    <loc xlink:href="dy-20150425.xsd#dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" xlink:label="loc_dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_64D8BD41C6839A171294700C46568068" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_3BFA817D86FD555E98EF700C4656442C" xlink:to="loc_dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_64D8BD41C6839A171294700C46568068" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_E5EE27626A92F5919AC1700C46567F2C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_64D8BD41C6839A171294700C46568068" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_E5EE27626A92F5919AC1700C46567F2C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_7B2155302F9E5D4F708B700C465680F8_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_E5EE27626A92F5919AC1700C46567F2C" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_7B2155302F9E5D4F708B700C465680F8_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_7B2155302F9E5D4F708B700C465680F8" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_E5EE27626A92F5919AC1700C46567F2C" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_7B2155302F9E5D4F708B700C465680F8" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_UtiliquestMember" xlink:label="loc_dy_UtiliquestMember_5F64FD3DD48D184DE628700C4656A616" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_7B2155302F9E5D4F708B700C465680F8" xlink:to="loc_dy_UtiliquestMember_5F64FD3DD48D184DE628700C4656A616" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_0C42250EEA34FF67FF4A700C4656C99B" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dy_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_64D8BD41C6839A171294700C46568068" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_0C42250EEA34FF67FF4A700C4656C99B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_E51788B64DB36130C1B7700C465684CB_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_0C42250EEA34FF67FF4A700C4656C99B" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_E51788B64DB36130C1B7700C465684CB_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_E51788B64DB36130C1B7700C465684CB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_0C42250EEA34FF67FF4A700C4656C99B" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_E51788B64DB36130C1B7700C465684CB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_77D4E83F67914ABEA8F4700C4656928C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_E51788B64DB36130C1B7700C465684CB" xlink:to="loc_us-gaap_CustomerRelationshipsMember_77D4E83F67914ABEA8F4700C4656928C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OrderOrProductionBacklogMember" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_029050D41A621C787030700C4656A158" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_E51788B64DB36130C1B7700C465684CB" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_029050D41A621C787030700C4656A158" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="loc_us-gaap_TradeNamesMember_3990018DF27CE1AF98F0700C46568FCD" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_E51788B64DB36130C1B7700C465684CB" xlink:to="loc_us-gaap_TradeNamesMember_3990018DF27CE1AF98F0700C46568FCD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NoncompeteAgreementsMember" xlink:label="loc_us-gaap_NoncompeteAgreementsMember_ABABE41FDF218CB601B5700C465634D5" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_E51788B64DB36130C1B7700C465684CB" xlink:to="loc_us-gaap_NoncompeteAgreementsMember_ABABE41FDF218CB601B5700C465634D5" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_66834BE30B9C880BCD72700C46569E9A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_3BFA817D86FD555E98EF700C4656442C" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_66834BE30B9C880BCD72700C46569E9A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_0D1620A2745CABD5EE11700C4656A354" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_3BFA817D86FD555E98EF700C4656442C" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_0D1620A2745CABD5EE11700C4656A354" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_4936FB5EC69E49701F49700C4656A5BB" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_3BFA817D86FD555E98EF700C4656442C" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_4936FB5EC69E49701F49700C4656A5BB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_FB8654A4003E18F97C76700C46563030" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_3BFA817D86FD555E98EF700C4656442C" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_FB8654A4003E18F97C76700C46563030" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_36592E43962941627600700C46560606" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dy_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_3BFA817D86FD555E98EF700C4656442C" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_36592E43962941627600700C46560606" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/GoodwillAndIntangibleAssetsTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/IncomeTaxes" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/IncomeTaxesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLossCarryforwardsLineItems" xlink:label="loc_us-gaap_OperatingLossCarryforwardsLineItems_A5763B15BEA9E4180F02700C471225D5" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLossCarryforwardsTable" xlink:label="loc_us-gaap_OperatingLossCarryforwardsTable_7A23722278A48DDE876A700C471212BA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_A5763B15BEA9E4180F02700C471225D5" xlink:to="loc_us-gaap_OperatingLossCarryforwardsTable_7A23722278A48DDE876A700C471212BA" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_C28276F4BC4F1B9492B0700C47124123" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_7A23722278A48DDE876A700C471212BA" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_C28276F4BC4F1B9492B0700C47124123" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_0DDD178282E502B4A7E3700C471260A3_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_C28276F4BC4F1B9492B0700C47124123" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_0DDD178282E502B4A7E3700C471260A3_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_0DDD178282E502B4A7E3700C471260A3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_C28276F4BC4F1B9492B0700C47124123" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_0DDD178282E502B4A7E3700C471260A3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherAssetsMember" xlink:label="loc_us-gaap_OtherAssetsMember_54E1147474DC61762692700C47125AB3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_0DDD178282E502B4A7E3700C471260A3" xlink:to="loc_us-gaap_OtherAssetsMember_54E1147474DC61762692700C47125AB3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeTaxesReceivable" xlink:label="loc_us-gaap_IncomeTaxesReceivable_60164F56EE0EBE1D7A34700C4712600C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_A5763B15BEA9E4180F02700C471225D5" xlink:to="loc_us-gaap_IncomeTaxesReceivable_60164F56EE0EBE1D7A34700C4712600C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_TaxesPayableCurrent" xlink:label="loc_us-gaap_TaxesPayableCurrent_BA5D63D6CBD73D9DBF68700C471201FB" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_A5763B15BEA9E4180F02700C471225D5" xlink:to="loc_us-gaap_TaxesPayableCurrent_BA5D63D6CBD73D9DBF68700C471201FB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_8A7C68C76F68A8CEC3C4700C4712612F" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_A5763B15BEA9E4180F02700C471225D5" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_8A7C68C76F68A8CEC3C4700C4712612F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_FBB8B2F3BA467C5828B2700C47127E51" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_A5763B15BEA9E4180F02700C471225D5" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_FBB8B2F3BA467C5828B2700C47127E51" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/OtherAccruedLiabilities" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/OtherAccruedLiabilitiesDetails" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/OtherAccruedLiabilitiesTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/OtherIncomeNet" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/OtherIncomeNetDetails" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/OtherIncomeNetTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/PropertyAndEquipment" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/PropertyAndEquipmentDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_8EC15A18998A8EBA2DC4700C46F2094D" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9B0376A2BABE798A0B2C700C46F2F152" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_8EC15A18998A8EBA2DC4700C46F2094D" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9B0376A2BABE798A0B2C700C46F2F152" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_6508411C4108219F2268700C46F27CC9" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9B0376A2BABE798A0B2C700C46F2F152" xlink:to="loc_us-gaap_RangeAxis_6508411C4108219F2268700C46F27CC9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_AD8683277925B70E8462700C46F27B7C_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_6508411C4108219F2268700C46F27CC9" xlink:to="loc_us-gaap_RangeMember_AD8683277925B70E8462700C46F27B7C_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_AD8683277925B70E8462700C46F27B7C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_6508411C4108219F2268700C46F27CC9" xlink:to="loc_us-gaap_RangeMember_AD8683277925B70E8462700C46F27B7C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_E5F23175BC4F4CBE1766700C46F22599" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_AD8683277925B70E8462700C46F27B7C" xlink:to="loc_us-gaap_MinimumMember_E5F23175BC4F4CBE1766700C46F22599" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_F7F88CFC8468F695F9DF700C46F2774D" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_AD8683277925B70E8462700C46F27B7C" xlink:to="loc_us-gaap_MaximumMember_F7F88CFC8468F695F9DF700C46F2774D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_94718238C8ABE7BE3DCC700C46F27DEF" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9B0376A2BABE798A0B2C700C46F2F152" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_94718238C8ABE7BE3DCC700C46F27DEF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5A81791C023E4CA4D316700C46F2F41A_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_94718238C8ABE7BE3DCC700C46F27DEF" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5A81791C023E4CA4D316700C46F2F41A_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5A81791C023E4CA4D316700C46F2F41A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_94718238C8ABE7BE3DCC700C46F27DEF" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5A81791C023E4CA4D316700C46F2F41A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LandMember" xlink:label="loc_us-gaap_LandMember_DC76E35F6618AB22D949700C46F2F170" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5A81791C023E4CA4D316700C46F2F41A" xlink:to="loc_us-gaap_LandMember_DC76E35F6618AB22D949700C46F2F170" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BuildingMember" xlink:label="loc_us-gaap_BuildingMember_EB9175F3AE685D53284A700C46F20FA0" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5A81791C023E4CA4D316700C46F2F41A" xlink:to="loc_us-gaap_BuildingMember_EB9175F3AE685D53284A700C46F20FA0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_B81A71A887B43890E155700C46F288CD" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5A81791C023E4CA4D316700C46F2F41A" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_B81A71A887B43890E155700C46F288CD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_VehiclesMember" xlink:label="loc_us-gaap_VehiclesMember_B56F2ED8DD8D8E2D8782700C46F25FBF" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5A81791C023E4CA4D316700C46F2F41A" xlink:to="loc_us-gaap_VehiclesMember_B56F2ED8DD8D8E2D8782700C46F25FBF" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_ComputerHardwareAndSoftwareMember" xlink:label="loc_dy_ComputerHardwareAndSoftwareMember_4E09E85222181E71DB13700C46F253EF" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5A81791C023E4CA4D316700C46F2F41A" xlink:to="loc_dy_ComputerHardwareAndSoftwareMember_4E09E85222181E71DB13700C46F253EF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_07521CDF6FA04DA5DA42700C46F2B89B" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5A81791C023E4CA4D316700C46F2F41A" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_07521CDF6FA04DA5DA42700C46F2B89B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MachineryAndEquipmentMember" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_5ED3C089A0F243888067700C46F2D668" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5A81791C023E4CA4D316700C46F2F41A" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_5ED3C089A0F243888067700C46F2D668" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_F84E6936C3ECFC0A3D7E700C46F224AA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_8EC15A18998A8EBA2DC4700C46F2094D" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_F84E6936C3ECFC0A3D7E700C46F224AA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_A7A06BD18C56D9D99CD5700C46F2342C" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_8EC15A18998A8EBA2DC4700C46F2094D" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_A7A06BD18C56D9D99CD5700C46F2342C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_85AF94315A9243C95526700C46F2456D" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_8EC15A18998A8EBA2DC4700C46F2094D" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_85AF94315A9243C95526700C46F2456D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_1584381CA24948A49E56700C46F2A1B4" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_8EC15A18998A8EBA2DC4700C46F2094D" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_1584381CA24948A49E56700C46F2A1B4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Depreciation" xlink:label="loc_us-gaap_Depreciation_E476B23A60B6CE82C193700C46F2B6AC" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_8EC15A18998A8EBA2DC4700C46F2094D" xlink:to="loc_us-gaap_Depreciation_E476B23A60B6CE82C193700C46F2B6AC" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/PropertyAndEquipmentTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/RelatedPartyTransactions" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/RelatedPartyTransactionsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_F35ED8F4D7FB82E68F47700C46C4B596" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_F4D8E2AC75EE820BEB31700C46C4DA53" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_F35ED8F4D7FB82E68F47700C46C4B596" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_F4D8E2AC75EE820BEB31700C46C4DA53" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_FF2C0FAFE3C5B78BFF13700C46C4F8F0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_F4D8E2AC75EE820BEB31700C46C4DA53" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_FF2C0FAFE3C5B78BFF13700C46C4F8F0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_5656F3985DCE47A32E0C700C46C42CE7_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_FF2C0FAFE3C5B78BFF13700C46C4F8F0" xlink:to="loc_us-gaap_RelatedPartyDomain_5656F3985DCE47A32E0C700C46C42CE7_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_5656F3985DCE47A32E0C700C46C42CE7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_FF2C0FAFE3C5B78BFF13700C46C4F8F0" xlink:to="loc_us-gaap_RelatedPartyDomain_5656F3985DCE47A32E0C700C46C42CE7" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_RealpropertyandequipmentleasesMember" xlink:label="loc_dy_RealpropertyandequipmentleasesMember_A15CDDB25ACA1E5C5FD3700C46C43C78" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_5656F3985DCE47A32E0C700C46C42CE7" xlink:to="loc_dy_RealpropertyandequipmentleasesMember_A15CDDB25ACA1E5C5FD3700C46C43C78" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_SubcontractorsandmaterialsexpenseMember" xlink:label="loc_dy_SubcontractorsandmaterialsexpenseMember_DC0DFFD7625D58E531AE700C46C40EFF" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_5656F3985DCE47A32E0C700C46C42CE7" xlink:to="loc_dy_SubcontractorsandmaterialsexpenseMember_DC0DFFD7625D58E531AE700C46C40EFF" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty" xlink:label="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_8AC1BCABB141BAA0D047700C46C4372F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_F35ED8F4D7FB82E68F47700C46C4B596" xlink:to="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_8AC1BCABB141BAA0D047700C46C4372F" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/RelatedPartyTransactionsTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/StockBasedAwards" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/StockBasedAwardsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B1947807CE3CDA2F30F868E5EF993836" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_079988E357DF76ACE25468E5EF975039" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B1947807CE3CDA2F30F868E5EF993836" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_079988E357DF76ACE25468E5EF975039" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_4F4FB6102F6B167189CF68E5EF983CFB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_079988E357DF76ACE25468E5EF975039" xlink:to="loc_us-gaap_AwardTypeAxis_4F4FB6102F6B167189CF68E5EF983CFB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FC74EAD542952ACDA3CC68E5EF98B295_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_4F4FB6102F6B167189CF68E5EF983CFB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FC74EAD542952ACDA3CC68E5EF98B295_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FC74EAD542952ACDA3CC68E5EF98B295" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_4F4FB6102F6B167189CF68E5EF983CFB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FC74EAD542952ACDA3CC68E5EF98B295" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_3CB2BEBE0284A35F567368E5EF986389" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FC74EAD542952ACDA3CC68E5EF98B295" xlink:to="loc_us-gaap_EmployeeStockOptionMember_3CB2BEBE0284A35F567368E5EF986389" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_9953FFCEEA607A07843B68E5EF988095" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FC74EAD542952ACDA3CC68E5EF98B295" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_9953FFCEEA607A07843B68E5EF988095" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PerformanceSharesMember" xlink:label="loc_us-gaap_PerformanceSharesMember_F1FF3643705AF606B80368E5EF98146C" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FC74EAD542952ACDA3CC68E5EF98B295" xlink:to="loc_us-gaap_PerformanceSharesMember_F1FF3643705AF606B80368E5EF98146C" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_TargetSharesMember" xlink:label="loc_dy_TargetSharesMember_6A7362F224D2E494C62168E5EF986215" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PerformanceSharesMember_F1FF3643705AF606B80368E5EF98146C" xlink:to="loc_dy_TargetSharesMember_6A7362F224D2E494C62168E5EF986215" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_SupplementalSharesMember" xlink:label="loc_dy_SupplementalSharesMember_062071FC917942697ADC68E5EF9816A1" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PerformanceSharesMember_F1FF3643705AF606B80368E5EF98146C" xlink:to="loc_dy_SupplementalSharesMember_062071FC917942697ADC68E5EF9816A1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_75B581951225FAD21BDD68E5EF99A65D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B1947807CE3CDA2F30F868E5EF993836" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_75B581951225FAD21BDD68E5EF99A65D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_BD94AE13C9D1FE84B91F68E5EF99F9FE" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B1947807CE3CDA2F30F868E5EF993836" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_BD94AE13C9D1FE84B91F68E5EF99F9FE" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_PotentialCompensationExpenseForPerformanceBasedSharesIfPerformanceGoalsAreMet" xlink:label="loc_dy_PotentialCompensationExpenseForPerformanceBasedSharesIfPerformanceGoalsAreMet_9C47F2A1907BA44B676A68E5EF99721E" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B1947807CE3CDA2F30F868E5EF993836" xlink:to="loc_dy_PotentialCompensationExpenseForPerformanceBasedSharesIfPerformanceGoalsAreMet_9C47F2A1907BA44B676A68E5EF99721E" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_ShareBasedCompensationByShareBasedPaymentAwardEquityAwardsOtherThanOptionsTargetAmount" xlink:label="loc_dy_ShareBasedCompensationByShareBasedPaymentAwardEquityAwardsOtherThanOptionsTargetAmount_107C5C4919D60D9BD8FB68E5EF997597" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B1947807CE3CDA2F30F868E5EF993836" xlink:to="loc_dy_ShareBasedCompensationByShareBasedPaymentAwardEquityAwardsOtherThanOptionsTargetAmount_107C5C4919D60D9BD8FB68E5EF997597" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_DBE9D8C31EF31687A94D68E5EF99AD7F" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B1947807CE3CDA2F30F868E5EF993836" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_DBE9D8C31EF31687A94D68E5EF99AD7F" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsCancelledinPeriod" xlink:label="loc_dy_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsCancelledinPeriod_8000EC595E8FDFDEB36C68E5EF991B93" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B1947807CE3CDA2F30F868E5EF993836" xlink:to="loc_dy_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsCancelledinPeriod_8000EC595E8FDFDEB36C68E5EF991B93" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_SharebasedCompensationbySharebasedPaymentAwardEquityAwardsOtherthanOptionsTargetSharesExpectedtobeCanceled" xlink:label="loc_dy_SharebasedCompensationbySharebasedPaymentAwardEquityAwardsOtherthanOptionsTargetSharesExpectedtobeCanceled_DF804F8E8853F7B721AA68E5EF9A403A" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B1947807CE3CDA2F30F868E5EF993836" xlink:to="loc_dy_SharebasedCompensationbySharebasedPaymentAwardEquityAwardsOtherthanOptionsTargetSharesExpectedtobeCanceled_DF804F8E8853F7B721AA68E5EF9A403A" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_SharebasedCompensationbySharebasedPaymentAwardEquityAwardsOtherthanOptionsSupplementalSharesExpectedtobeCanceled" xlink:label="loc_dy_SharebasedCompensationbySharebasedPaymentAwardEquityAwardsOtherthanOptionsSupplementalSharesExpectedtobeCanceled_1A6AA6405437D79FE37068E5EF9AAE90" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B1947807CE3CDA2F30F868E5EF993836" xlink:to="loc_dy_SharebasedCompensationbySharebasedPaymentAwardEquityAwardsOtherthanOptionsSupplementalSharesExpectedtobeCanceled_1A6AA6405437D79FE37068E5EF9AAE90" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_126CDF663164FB64CD0C68E5EF9AC52C" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B1947807CE3CDA2F30F868E5EF993836" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_126CDF663164FB64CD0C68E5EF9AC52C" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/StockBasedAwardsRsusAndPerformanceRsusDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_62E3D4EB96392BA4875D700C4685741F" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_506BBFE179031977217F700C46851440" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_62E3D4EB96392BA4875D700C4685741F" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_506BBFE179031977217F700C46851440" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_0FD2F118CE20C7231197700C4685586C" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_506BBFE179031977217F700C46851440" xlink:to="loc_us-gaap_AwardTypeAxis_0FD2F118CE20C7231197700C4685586C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8FDF88AD6384B960DB6B700C46854762_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_0FD2F118CE20C7231197700C4685586C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8FDF88AD6384B960DB6B700C46854762_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8FDF88AD6384B960DB6B700C46854762" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_0FD2F118CE20C7231197700C4685586C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8FDF88AD6384B960DB6B700C46854762" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_124229B0950675C93DCF700C46851661" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8FDF88AD6384B960DB6B700C46854762" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_124229B0950675C93DCF700C46851661" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PerformanceSharesMember" xlink:label="loc_us-gaap_PerformanceSharesMember_C1E9CD85FD7A9C4D7753700C4685B977" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8FDF88AD6384B960DB6B700C46854762" xlink:to="loc_us-gaap_PerformanceSharesMember_C1E9CD85FD7A9C4D7753700C4685B977" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_73C8096EA36AC6397B2C700C4685E3C8" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_62E3D4EB96392BA4875D700C4685741F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_73C8096EA36AC6397B2C700C4685E3C8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_D3A8AADDE578C0D384F1700C4685EBCD" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_73C8096EA36AC6397B2C700C4685E3C8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_D3A8AADDE578C0D384F1700C4685EBCD" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_0103FDB82DE17C4D1DF4700C46855A8E" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_73C8096EA36AC6397B2C700C4685E3C8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_0103FDB82DE17C4D1DF4700C46855A8E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_0194F0B26E8A3A7B75C6700C46853FBC" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_73C8096EA36AC6397B2C700C4685E3C8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_0194F0B26E8A3A7B75C6700C46853FBC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_E9B73D985F97DCFA068C700C468584DC" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward_73C8096EA36AC6397B2C700C4685E3C8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_E9B73D985F97DCFA068C700C468584DC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_24231F7550ED8A695D37700C4685E20B" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_62E3D4EB96392BA4875D700C4685741F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_24231F7550ED8A695D37700C4685E20B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_17ABCF15A7F39B77694A700C46852865" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_24231F7550ED8A695D37700C4685E20B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_17ABCF15A7F39B77694A700C46852865" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_ADC1469BA1DC10940338700C46852DE4" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_24231F7550ED8A695D37700C4685E20B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_ADC1469BA1DC10940338700C46852DE4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_6F3E5172A4BC2605D2EB700C4685924B" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_24231F7550ED8A695D37700C4685E20B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_6F3E5172A4BC2605D2EB700C4685924B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_E81FE4A784003F941EE9700C46856069" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_24231F7550ED8A695D37700C4685E20B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_E81FE4A784003F941EE9700C46856069" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/StockBasedAwardsStockOptionsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_96A1002E50D84319C64F700C45F98706" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4EACD8DAF8448865DB16700C45F994C5" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_96A1002E50D84319C64F700C45F98706" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4EACD8DAF8448865DB16700C45F994C5" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_EAE72E9776899D568EB0700C45F9B2C6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4EACD8DAF8448865DB16700C45F994C5" xlink:to="loc_us-gaap_AwardTypeAxis_EAE72E9776899D568EB0700C45F9B2C6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4B9D9E8E2AED85A99DC1700C45F9115E_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_EAE72E9776899D568EB0700C45F9B2C6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4B9D9E8E2AED85A99DC1700C45F9115E_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4B9D9E8E2AED85A99DC1700C45F9115E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_EAE72E9776899D568EB0700C45F9B2C6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4B9D9E8E2AED85A99DC1700C45F9115E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_74F7718B5A15102BBA95700C45F9A7CA" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4B9D9E8E2AED85A99DC1700C45F9115E" xlink:to="loc_us-gaap_EmployeeStockOptionMember_74F7718B5A15102BBA95700C45F9A7CA" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_2405E387DA21EF359E96700C45F9F292" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_96A1002E50D84319C64F700C45F98706" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_2405E387DA21EF359E96700C45F9F292" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_5C630AC2529CECA6652D700C45F9097D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_2405E387DA21EF359E96700C45F9F292" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_5C630AC2529CECA6652D700C45F9097D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_EC755887306AA6465E09700C45F99ADC" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_2405E387DA21EF359E96700C45F9F292" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_EC755887306AA6465E09700C45F99ADC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_185EB9DACE7ED9678E48700C45F99C85" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_2405E387DA21EF359E96700C45F9F292" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_185EB9DACE7ED9678E48700C45F99C85" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_B9546AB8E4DB0203F990700C45F9B3A0" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_2405E387DA21EF359E96700C45F9F292" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_B9546AB8E4DB0203F990700C45F9B3A0" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_CBC09F04C934AB28CDEE700C45F9524C" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_2405E387DA21EF359E96700C45F9F292" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_CBC09F04C934AB28CDEE700C45F9524C" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_3C2C4D5EB74A702CF6D6700C45F96107" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_96A1002E50D84319C64F700C45F98706" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_3C2C4D5EB74A702CF6D6700C45F96107" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_5D87DB23C2ECB97E0CAD700C45F9939F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_3C2C4D5EB74A702CF6D6700C45F96107" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_5D87DB23C2ECB97E0CAD700C45F9939F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_C24039E105B3A27173E2700C45F977A1" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_3C2C4D5EB74A702CF6D6700C45F96107" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_C24039E105B3A27173E2700C45F977A1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_1F424EB78845A7D522BE700C45F9E2BC" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_3C2C4D5EB74A702CF6D6700C45F96107" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_1F424EB78845A7D522BE700C45F9E2BC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_CE2C0D43BD745214DF9E700C45F9BB37" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_3C2C4D5EB74A702CF6D6700C45F96107" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_CE2C0D43BD745214DF9E700C45F9BB37" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_D4C809405F3872C45C70700C45F9779D" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_3C2C4D5EB74A702CF6D6700C45F96107" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_D4C809405F3872C45C70700C45F9779D" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/StockBasedAwardsTables" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/StockBasedAwardsTaxBenefitRecognizedDetails" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatements" xlink:type="extended" />
  <definitionLink xlink:role="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatementsBalanceSheetDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CondensedFinancialStatementsCaptionsLineItems" xlink:label="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_98E8B0B31A4A93D0153168E5EF3CEABA" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfCondensedFinancialStatementsTable" xlink:label="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_31BFDB7141E07488D3ED68E5EF3B8985" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_98E8B0B31A4A93D0153168E5EF3CEABA" xlink:to="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_31BFDB7141E07488D3ED68E5EF3B8985" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_F4784FD207D78C32E24F68E5EF3B0DB3" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_31BFDB7141E07488D3ED68E5EF3B8985" xlink:to="loc_dei_LegalEntityAxis_F4784FD207D78C32E24F68E5EF3B0DB3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_C848C13AABEDF229830368E5EF3BA20D_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_F4784FD207D78C32E24F68E5EF3B0DB3" xlink:to="loc_dei_EntityDomain_C848C13AABEDF229830368E5EF3BA20D_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_C848C13AABEDF229830368E5EF3BA20D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_F4784FD207D78C32E24F68E5EF3B0DB3" xlink:to="loc_dei_EntityDomain_C848C13AABEDF229830368E5EF3BA20D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ParentCompanyMember" xlink:label="loc_us-gaap_ParentCompanyMember_08B55F5F850F5904B9FB68E5EF3B75D1" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_C848C13AABEDF229830368E5EF3BA20D" xlink:to="loc_us-gaap_ParentCompanyMember_08B55F5F850F5904B9FB68E5EF3B75D1" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_IssuerMember" xlink:label="loc_dy_IssuerMember_A0FAC135D416B2F3E8C968E5EF3B3C09" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_C848C13AABEDF229830368E5EF3BA20D" xlink:to="loc_dy_IssuerMember_A0FAC135D416B2F3E8C968E5EF3B3C09" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GuarantorSubsidiariesMember" xlink:label="loc_us-gaap_GuarantorSubsidiariesMember_A7C0FDB132DE34CEECF968E5EF3BCE86" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_C848C13AABEDF229830368E5EF3BA20D" xlink:to="loc_us-gaap_GuarantorSubsidiariesMember_A7C0FDB132DE34CEECF968E5EF3BCE86" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NonGuarantorSubsidiariesMember" xlink:label="loc_us-gaap_NonGuarantorSubsidiariesMember_30AB2A2CF2CB84092CEB68E5EF3B7402" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_C848C13AABEDF229830368E5EF3BA20D" xlink:to="loc_us-gaap_NonGuarantorSubsidiariesMember_30AB2A2CF2CB84092CEB68E5EF3B7402" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConsolidationEliminationsMember" xlink:label="loc_us-gaap_ConsolidationEliminationsMember_5C417B315FFD41F5CB3F68E5EF3BF856" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_C848C13AABEDF229830368E5EF3BA20D" xlink:to="loc_us-gaap_ConsolidationEliminationsMember_5C417B315FFD41F5CB3F68E5EF3BF856" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_98E8B0B31A4A93D0153168E5EF3CEABA" xlink:to="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="loc_us-gaap_AssetsCurrentAbstract_78F47927D4587CF7D16968E5EF3C3AF7" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:to="loc_us-gaap_AssetsCurrentAbstract_78F47927D4587CF7D16968E5EF3C3AF7" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_A71BED6294882E5E0E6868E5EF3CC909" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_78F47927D4587CF7D16968E5EF3C3AF7" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_A71BED6294882E5E0E6868E5EF3CC909" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_8DC2C9E7C67E6791B24768E5EF3CDFFB" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_78F47927D4587CF7D16968E5EF3C3AF7" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_8DC2C9E7C67E6791B24768E5EF3CDFFB" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_CostsAndEstimatedEarningsInExcessOfBillings" xlink:label="loc_dy_CostsAndEstimatedEarningsInExcessOfBillings_F01336581A881FB9181768E5EF3C8EF2" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_78F47927D4587CF7D16968E5EF3C3AF7" xlink:to="loc_dy_CostsAndEstimatedEarningsInExcessOfBillings_F01336581A881FB9181768E5EF3C8EF2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_819D7B21AAA729F60E3068E5EF3C720B" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_78F47927D4587CF7D16968E5EF3C3AF7" xlink:to="loc_us-gaap_InventoryNet_819D7B21AAA729F60E3068E5EF3C720B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredTaxAssetsNetCurrent" xlink:label="loc_us-gaap_DeferredTaxAssetsNetCurrent_DCA38EEF5D7E68F6CB2C68E5EF3D94C1" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_78F47927D4587CF7D16968E5EF3C3AF7" xlink:to="loc_us-gaap_DeferredTaxAssetsNetCurrent_DCA38EEF5D7E68F6CB2C68E5EF3D94C1" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="loc_us-gaap_OtherAssetsCurrent_2045B6BBCD022D94256B68E5EF3DAD2E" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_78F47927D4587CF7D16968E5EF3C3AF7" xlink:to="loc_us-gaap_OtherAssetsCurrent_2045B6BBCD022D94256B68E5EF3DAD2E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_FA7A4CCF75B504A3039C68E5EF3D0046" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_78F47927D4587CF7D16968E5EF3C3AF7" xlink:to="loc_us-gaap_AssetsCurrent_FA7A4CCF75B504A3039C68E5EF3D0046" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_44DFFF86629AC917526F68E5EF3D0898" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_44DFFF86629AC917526F68E5EF3D0898" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_43BC1FB991516F42509168E5EF3D576D" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:to="loc_us-gaap_Goodwill_43BC1FB991516F42509168E5EF3D576D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_DE70FB11A734ECD427E768E5EF3DC29A" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_DE70FB11A734ECD427E768E5EF3DC29A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredTaxAssetsNetNoncurrent" xlink:label="loc_us-gaap_DeferredTaxAssetsNetNoncurrent_E91897064B2639EB0B9768E5EF3D48E6" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:to="loc_us-gaap_DeferredTaxAssetsNetNoncurrent_E91897064B2639EB0B9768E5EF3D48E6" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_InvestmentInWhollyOwnedSubsidiaries" xlink:label="loc_dy_InvestmentInWhollyOwnedSubsidiaries_98B94129CF062D7ECD9068E5EF3D22FC" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:to="loc_dy_InvestmentInWhollyOwnedSubsidiaries_98B94129CF062D7ECD9068E5EF3D22FC" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_IntercompanyReceivablesAggregate" xlink:label="loc_dy_IntercompanyReceivablesAggregate_C34322CFE6FD5101234368E5EF3DC66F" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:to="loc_dy_IntercompanyReceivablesAggregate_C34322CFE6FD5101234368E5EF3DC66F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_B24FC0EF656C75878A3468E5EF3DA07E" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_B24FC0EF656C75878A3468E5EF3DA07E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsNoncurrent" xlink:label="loc_us-gaap_AssetsNoncurrent_11B1137DFC9EDF40080368E5EF3D20C4" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:to="loc_us-gaap_AssetsNoncurrent_11B1137DFC9EDF40080368E5EF3D20C4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_99F01FB5EF1BCFF8F63E68E5EF3E0C9D" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_804FA8270609A594A6AF68E5EF3C725A" xlink:to="loc_us-gaap_Assets_99F01FB5EF1BCFF8F63E68E5EF3E0C9D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_82257D66BA20DAE688FC68E5EF3E4238" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_98E8B0B31A4A93D0153168E5EF3CEABA" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_82257D66BA20DAE688FC68E5EF3E4238" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_A9851D09AF17BA9697A668E5EF3E259E" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_82257D66BA20DAE688FC68E5EF3E4238" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_A9851D09AF17BA9697A668E5EF3E259E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent_C26BC8530884250FD6BA68E5EF3EFD25" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_A9851D09AF17BA9697A668E5EF3E259E" xlink:to="loc_us-gaap_AccountsPayableCurrent_C26BC8530884250FD6BA68E5EF3EFD25" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtCurrent" xlink:label="loc_us-gaap_DebtCurrent_0D0411C805C8736E15E768E5EF3E5265" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_A9851D09AF17BA9697A668E5EF3E259E" xlink:to="loc_us-gaap_DebtCurrent_0D0411C805C8736E15E768E5EF3E5265" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_BillingsInExcessOfCostsAndEstimatedEarnings" xlink:label="loc_dy_BillingsInExcessOfCostsAndEstimatedEarnings_1AD6D33C084EE333C6CB68E5EF3E0344" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_A9851D09AF17BA9697A668E5EF3E259E" xlink:to="loc_dy_BillingsInExcessOfCostsAndEstimatedEarnings_1AD6D33C084EE333C6CB68E5EF3E0344" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_AccruedInsuranceClaimsCurrent" xlink:label="loc_dy_AccruedInsuranceClaimsCurrent_243799E24BD1B231BAA568E5EF3F0DA3" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_A9851D09AF17BA9697A668E5EF3E259E" xlink:to="loc_dy_AccruedInsuranceClaimsCurrent_243799E24BD1B231BAA568E5EF3F0DA3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredTaxLiabilitiesCurrent" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesCurrent_3606D408645CF3BCF3C668E5EF3F834A" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_A9851D09AF17BA9697A668E5EF3E259E" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesCurrent_3606D408645CF3BCF3C668E5EF3F834A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesCurrent_AE1DA415D46315AE1A3468E5EF3F9A49" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_A9851D09AF17BA9697A668E5EF3E259E" xlink:to="loc_us-gaap_OtherAccruedLiabilitiesCurrent_AE1DA415D46315AE1A3468E5EF3F9A49" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_7214064FBBDF471DB35168E5EF3FE77E" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_A9851D09AF17BA9697A668E5EF3E259E" xlink:to="loc_us-gaap_LiabilitiesCurrent_7214064FBBDF471DB35168E5EF3FE77E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_D07AE4590873F6EBD43D68E5EF3FBD3D" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_82257D66BA20DAE688FC68E5EF3E4238" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_D07AE4590873F6EBD43D68E5EF3FBD3D" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_AccruedInsuranceClaimsNoncurrent" xlink:label="loc_dy_AccruedInsuranceClaimsNoncurrent_E3F9452C5B3E13F4A32168E5EF3F567E" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_82257D66BA20DAE688FC68E5EF3E4238" xlink:to="loc_dy_AccruedInsuranceClaimsNoncurrent_E3F9452C5B3E13F4A32168E5EF3F567E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredTaxLiabilitiesNoncurrent" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesNoncurrent_8913FFFE8C2E4BDE836D68E5EF3F9643" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_82257D66BA20DAE688FC68E5EF3E4238" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesNoncurrent_8913FFFE8C2E4BDE836D68E5EF3F9643" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_IntercompanyPayablesAggregate" xlink:label="loc_dy_IntercompanyPayablesAggregate_D9EE00BAAABB26E234CA68E5EF3FF376" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_82257D66BA20DAE688FC68E5EF3E4238" xlink:to="loc_dy_IntercompanyPayablesAggregate_D9EE00BAAABB26E234CA68E5EF3FF376" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_D83C28C64040C9621AC568E5EF3FD3FB" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_82257D66BA20DAE688FC68E5EF3E4238" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_D83C28C64040C9621AC568E5EF3FD3FB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_EB4AFDB89F6B025450B668E5EF3FB5D3" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_82257D66BA20DAE688FC68E5EF3E4238" xlink:to="loc_us-gaap_Liabilities_EB4AFDB89F6B025450B668E5EF3FB5D3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_97F338C753945135AA2A68E5EF3F9376" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_82257D66BA20DAE688FC68E5EF3E4238" xlink:to="loc_us-gaap_StockholdersEquity_97F338C753945135AA2A68E5EF3F9376" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_A10D6A264D04FDC71C6568E5EF3FF43B" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_82257D66BA20DAE688FC68E5EF3E4238" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_A10D6A264D04FDC71C6568E5EF3FF43B" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatementsCashFlowsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CondensedFinancialStatementsCaptionsLineItems" xlink:label="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_5DA528DA5EDDBEE730357846DDC5236F" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfCondensedFinancialStatementsTable" xlink:label="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_55A296205979B0B028867846DDC32125" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_5DA528DA5EDDBEE730357846DDC5236F" xlink:to="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_55A296205979B0B028867846DDC32125" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_BF1D0D88A1937187F9F87846DDC4B359" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_55A296205979B0B028867846DDC32125" xlink:to="loc_dei_LegalEntityAxis_BF1D0D88A1937187F9F87846DDC4B359" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_C40A8F619CEA4A6EBB997846DDC4672B_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_BF1D0D88A1937187F9F87846DDC4B359" xlink:to="loc_dei_EntityDomain_C40A8F619CEA4A6EBB997846DDC4672B_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_C40A8F619CEA4A6EBB997846DDC4672B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_BF1D0D88A1937187F9F87846DDC4B359" xlink:to="loc_dei_EntityDomain_C40A8F619CEA4A6EBB997846DDC4672B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ParentCompanyMember" xlink:label="loc_us-gaap_ParentCompanyMember_0968521572F771DE2AFE7846DDC4AE39" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_C40A8F619CEA4A6EBB997846DDC4672B" xlink:to="loc_us-gaap_ParentCompanyMember_0968521572F771DE2AFE7846DDC4AE39" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_IssuerMember" xlink:label="loc_dy_IssuerMember_3663CEE2B0278652558B7846DDC47EB2" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_C40A8F619CEA4A6EBB997846DDC4672B" xlink:to="loc_dy_IssuerMember_3663CEE2B0278652558B7846DDC47EB2" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GuarantorSubsidiariesMember" xlink:label="loc_us-gaap_GuarantorSubsidiariesMember_548D666FCD5F9F6F97EA7846DDC56635" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_C40A8F619CEA4A6EBB997846DDC4672B" xlink:to="loc_us-gaap_GuarantorSubsidiariesMember_548D666FCD5F9F6F97EA7846DDC56635" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NonGuarantorSubsidiariesMember" xlink:label="loc_us-gaap_NonGuarantorSubsidiariesMember_5D34E02AD8B6272BE4947846DDC515BB" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_C40A8F619CEA4A6EBB997846DDC4672B" xlink:to="loc_us-gaap_NonGuarantorSubsidiariesMember_5D34E02AD8B6272BE4947846DDC515BB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConsolidationEliminationsMember" xlink:label="loc_us-gaap_ConsolidationEliminationsMember_5F27D303064E397A044B7846DDC58022" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_C40A8F619CEA4A6EBB997846DDC4672B" xlink:to="loc_us-gaap_ConsolidationEliminationsMember_5F27D303064E397A044B7846DDC58022" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_A2F74FF673B4556254967846DDC64576" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_5DA528DA5EDDBEE730357846DDC5236F" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_A2F74FF673B4556254967846DDC64576" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9099B4B5CC7DC9A59EB27846DDC7D302" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_5DA528DA5EDDBEE730357846DDC5236F" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9099B4B5CC7DC9A59EB27846DDC7D302" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_E6ADB65C6F47A25398057846DDCDE0EB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9099B4B5CC7DC9A59EB27846DDC7D302" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_E6ADB65C6F47A25398057846DDCDE0EB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_252AA389E57368A2AD317846DDCD1912" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9099B4B5CC7DC9A59EB27846DDC7D302" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_252AA389E57368A2AD317846DDCD1912" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromSaleOfProductiveAssets" xlink:label="loc_us-gaap_ProceedsFromSaleOfProductiveAssets_24E8ADECB75840225A647846DDCD1D01" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9099B4B5CC7DC9A59EB27846DDC7D302" xlink:to="loc_us-gaap_ProceedsFromSaleOfProductiveAssets_24E8ADECB75840225A647846DDCD1D01" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_CapitalContributionToSubsidiaries" xlink:label="loc_dy_CapitalContributionToSubsidiaries_EDE42339062012D3FBAF7846DDCD3309" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9099B4B5CC7DC9A59EB27846DDC7D302" xlink:to="loc_dy_CapitalContributionToSubsidiaries_EDE42339062012D3FBAF7846DDCD3309" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_InvestmentInSubsidiaries" xlink:label="loc_dy_InvestmentInSubsidiaries_CF0706C46E70A7E855C37846DDCDDB95" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9099B4B5CC7DC9A59EB27846DDC7D302" xlink:to="loc_dy_InvestmentInSubsidiaries_CF0706C46E70A7E855C37846DDCDDB95" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInRestrictedCash" xlink:label="loc_us-gaap_IncreaseDecreaseInRestrictedCash_4609B4B9032B5870FFD17846DDCD6DF9" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9099B4B5CC7DC9A59EB27846DDC7D302" xlink:to="loc_us-gaap_IncreaseDecreaseInRestrictedCash_4609B4B9032B5870FFD17846DDCD6DF9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:label="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_BE411AED7CCE4E24D593785237B4335A" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9099B4B5CC7DC9A59EB27846DDC7D302" xlink:to="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_BE411AED7CCE4E24D593785237B4335A" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_8F501146586E91A9F38F7846DDCD848E" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9099B4B5CC7DC9A59EB27846DDC7D302" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_8F501146586E91A9F38F7846DDCD848E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_5DA528DA5EDDBEE730357846DDC5236F" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromLongTermLinesOfCredit" xlink:label="loc_us-gaap_ProceedsFromLongTermLinesOfCredit_A5CF57DCC45C587DCBAF7846DDCDF364" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:to="loc_us-gaap_ProceedsFromLongTermLinesOfCredit_A5CF57DCC45C587DCBAF7846DDCDF364" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RepaymentsOfLongTermLinesOfCredit" xlink:label="loc_us-gaap_RepaymentsOfLongTermLinesOfCredit_3682E0922F92267873EA7846DDCE1B71" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:to="loc_us-gaap_RepaymentsOfLongTermLinesOfCredit_3682E0922F92267873EA7846DDCE1B71" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtIssuanceCosts" xlink:label="loc_us-gaap_DebtIssuanceCosts_82745881578A2E3158857846DDCE136F" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:to="loc_us-gaap_DebtIssuanceCosts_82745881578A2E3158857846DDCE136F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_D5F45978E72AA2C7D6EA7846DDCE6663" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_D5F45978E72AA2C7D6EA7846DDCE6663" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_B8490192283EEE65E66C7846DDCEFAEE" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_B8490192283EEE65E66C7846DDCEFAEE" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_EAF7A362B96F278802F87846DDCE7A59" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_EAF7A362B96F278802F87846DDCE7A59" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:label="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities_9B215510AA524E8E24F67846DDCE0269" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:to="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities_9B215510AA524E8E24F67846DDCE0269" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:label="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_A9222049C5633D1A2B7F7846DDCF2DD9" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:to="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_A9222049C5633D1A2B7F7846DDCF2DD9" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromContributedCapital" xlink:label="loc_us-gaap_ProceedsFromContributedCapital_0FBCFF6A4E38735E67877846DDCFC74E" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:to="loc_us-gaap_ProceedsFromContributedCapital_0FBCFF6A4E38735E67877846DDCFC74E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_06981211E1C9E29BBD997846DDCFADD8" xlink:type="locator" />
    <definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_9E47C6FAAD3AB1DA5B007846DDCD339E" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_06981211E1C9E29BBD997846DDCFADD8" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_9FF5C88A172B24F331B37846DDCFE314" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_5DA528DA5EDDBEE730357846DDC5236F" xlink:to="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_9FF5C88A172B24F331B37846DDCFE314" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_0D4039B26A681C4508957846DDCF39CC" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_5DA528DA5EDDBEE730357846DDC5236F" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_0D4039B26A681C4508957846DDCF39CC" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatementsDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_ACA36A9BB9FE571E04DC700C46764D18" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_9C20CE357AE941B0FBA7700C4676B59F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ACA36A9BB9FE571E04DC700C46764D18" xlink:to="loc_us-gaap_DebtInstrumentTable_9C20CE357AE941B0FBA7700C4676B59F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_AD6B8042E983F8F52D9B700C4676FF8D" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9C20CE357AE941B0FBA7700C4676B59F" xlink:to="loc_us-gaap_DebtInstrumentAxis_AD6B8042E983F8F52D9B700C4676FF8D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1EE3DF2B9B07A86BEFB3700C46766919_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_AD6B8042E983F8F52D9B700C4676FF8D" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1EE3DF2B9B07A86BEFB3700C46766919_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1EE3DF2B9B07A86BEFB3700C46766919" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_AD6B8042E983F8F52D9B700C4676FF8D" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1EE3DF2B9B07A86BEFB3700C46766919" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member" xlink:label="loc_dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member_5E971BD0039B4364140D700C46763433" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_1EE3DF2B9B07A86BEFB3700C46766919" xlink:to="loc_dy_SevenPointOneTwoFivePercentSeniorSubordinatedNotesDue2021Member_5E971BD0039B4364140D700C46763433" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_9D85BB4CF8F93D025C65700C4676C966" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9C20CE357AE941B0FBA7700C4676B59F" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_9D85BB4CF8F93D025C65700C4676C966" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_B19D41DF50605E56765F700C46765444_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_9D85BB4CF8F93D025C65700C4676C966" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_B19D41DF50605E56765F700C46765444_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_B19D41DF50605E56765F700C46765444" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_9D85BB4CF8F93D025C65700C4676C966" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_B19D41DF50605E56765F700C46765444" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SeniorSubordinatedNotesMember" xlink:label="loc_us-gaap_SeniorSubordinatedNotesMember_8F28439277972565E2AB700C46769C4F" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_B19D41DF50605E56765F700C46765444" xlink:to="loc_us-gaap_SeniorSubordinatedNotesMember_8F28439277972565E2AB700C46769C4F" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtAndCapitalLeaseObligations" xlink:label="loc_us-gaap_DebtAndCapitalLeaseObligations_2061474F8CA5AC5A212B700C46760251" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ACA36A9BB9FE571E04DC700C46764D18" xlink:to="loc_us-gaap_DebtAndCapitalLeaseObligations_2061474F8CA5AC5A212B700C46760251" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatementsIncomeStatementDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CondensedFinancialStatementsCaptionsLineItems" xlink:label="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_75BEA26A311CE9E06519690C6012BDC3" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfCondensedFinancialStatementsTable" xlink:label="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_F69254E15F7A836CC201690C600CF0A0" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_75BEA26A311CE9E06519690C6012BDC3" xlink:to="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_F69254E15F7A836CC201690C600CF0A0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1C4D7B85ED16440D1EF9690C600CC4DB" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_F69254E15F7A836CC201690C600CF0A0" xlink:to="loc_dei_LegalEntityAxis_1C4D7B85ED16440D1EF9690C600CC4DB" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_779E91D57EE2A40E8962690C600CCF17_default" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1C4D7B85ED16440D1EF9690C600CC4DB" xlink:to="loc_dei_EntityDomain_779E91D57EE2A40E8962690C600CCF17_default" xlink:type="arc" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_779E91D57EE2A40E8962690C600CCF17" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1C4D7B85ED16440D1EF9690C600CC4DB" xlink:to="loc_dei_EntityDomain_779E91D57EE2A40E8962690C600CCF17" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ParentCompanyMember" xlink:label="loc_us-gaap_ParentCompanyMember_A04E7A2597E321EAE76E690C600C9BD6" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_779E91D57EE2A40E8962690C600CCF17" xlink:to="loc_us-gaap_ParentCompanyMember_A04E7A2597E321EAE76E690C600C9BD6" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_IssuerMember" xlink:label="loc_dy_IssuerMember_67F65E0AA7DCED071485690C600CDCF3" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_779E91D57EE2A40E8962690C600CCF17" xlink:to="loc_dy_IssuerMember_67F65E0AA7DCED071485690C600CDCF3" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GuarantorSubsidiariesMember" xlink:label="loc_us-gaap_GuarantorSubsidiariesMember_F4ED30BE188480FD0F6F690C600CD908" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_779E91D57EE2A40E8962690C600CCF17" xlink:to="loc_us-gaap_GuarantorSubsidiariesMember_F4ED30BE188480FD0F6F690C600CD908" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NonGuarantorSubsidiariesMember" xlink:label="loc_us-gaap_NonGuarantorSubsidiariesMember_A830CE0861E4A3C3C73D690C600D8047" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_779E91D57EE2A40E8962690C600CCF17" xlink:to="loc_us-gaap_NonGuarantorSubsidiariesMember_A830CE0861E4A3C3C73D690C600D8047" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConsolidationEliminationsMember" xlink:label="loc_us-gaap_ConsolidationEliminationsMember_27C2377EBD760F34B9B6690C60120968" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_779E91D57EE2A40E8962690C600CCF17" xlink:to="loc_us-gaap_ConsolidationEliminationsMember_27C2377EBD760F34B9B6690C60120968" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RevenuesAbstract" xlink:label="loc_us-gaap_RevenuesAbstract_C8AEE13D70F1AE1CF439690C60121826" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_75BEA26A311CE9E06519690C6012BDC3" xlink:to="loc_us-gaap_RevenuesAbstract_C8AEE13D70F1AE1CF439690C60121826" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SalesRevenueServicesNet" xlink:label="loc_us-gaap_SalesRevenueServicesNet_19D598D768E91F547BA9690C6012C403" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_C8AEE13D70F1AE1CF439690C60121826" xlink:to="loc_us-gaap_SalesRevenueServicesNet_19D598D768E91F547BA9690C6012C403" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="loc_us-gaap_OperatingExpensesAbstract_09B2A00F4BE9EC6A4FAC690C6012FEBC" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_75BEA26A311CE9E06519690C6012BDC3" xlink:to="loc_us-gaap_OperatingExpensesAbstract_09B2A00F4BE9EC6A4FAC690C6012FEBC" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CostOfServicesExcludingDepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_CostOfServicesExcludingDepreciationDepletionAndAmortization_387C85D58081ED49B45A690C60135B8B" xlink:type="locator" />
    <definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_09B2A00F4BE9EC6A4FAC690C6012FEBC" xlink:to="loc_us-gaap_CostOfServicesExcludingDepreciationDepletionAndAmortization_387C85D58081ED49B45A690C60135B8B" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_BFDB8D182655B130DFC9690C60135F90" xlink:type="locator" />
    <definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_09B2A00F4BE9EC6A4FAC690C6012FEBC" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_BFDB8D182655B130DFC9690C60135F90" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_C6DA799D8CF7E8EBFD90690C6013DFD7" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_09B2A00F4BE9EC6A4FAC690C6012FEBC" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_C6DA799D8CF7E8EBFD90690C6013DFD7" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_IntercompanyChargesIncome" xlink:label="loc_dy_IntercompanyChargesIncome_2752AA50C45AD6836689690C601389B4" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_09B2A00F4BE9EC6A4FAC690C6012FEBC" xlink:to="loc_dy_IntercompanyChargesIncome_2752AA50C45AD6836689690C601389B4" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InterestIncomeExpenseNet" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_74A3E931916341FFFE60690C60132B7E" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_09B2A00F4BE9EC6A4FAC690C6012FEBC" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_74A3E931916341FFFE60690C60132B7E" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_DFCC8CE201D0025C3C46690C6013A230" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_09B2A00F4BE9EC6A4FAC690C6012FEBC" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_DFCC8CE201D0025C3C46690C6013A230" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_584DCD475A75F948F57D690C6013C945" xlink:type="locator" />
    <definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_75BEA26A311CE9E06519690C6012BDC3" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_584DCD475A75F948F57D690C6013C945" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_BFBD2E195DAAE33DCED4690C6013361E" xlink:type="locator" />
    <definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_75BEA26A311CE9E06519690C6012BDC3" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_BFBD2E195DAAE33DCED4690C6013361E" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_NetIncomeLossBeforeEquityInEarningsOfSubsidiaries" xlink:label="loc_dy_NetIncomeLossBeforeEquityInEarningsOfSubsidiaries_12ECDB88371F0C7452FA690C6014C1D6" xlink:type="locator" />
    <definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_75BEA26A311CE9E06519690C6012BDC3" xlink:to="loc_dy_NetIncomeLossBeforeEquityInEarningsOfSubsidiaries_12ECDB88371F0C7452FA690C6014C1D6" xlink:type="arc" />
    <loc xlink:href="dy-20150425.xsd#dy_EquityInEarningsOfSubsidiaries" xlink:label="loc_dy_EquityInEarningsOfSubsidiaries_6A83E96C2AEEE98703C6690C60148CF6" xlink:type="locator" />
    <definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_75BEA26A311CE9E06519690C6012BDC3" xlink:to="loc_dy_EquityInEarningsOfSubsidiaries_6A83E96C2AEEE98703C6690C60148CF6" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_F393ECF3F87E20B1766A690C60142FED" xlink:type="locator" />
    <definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_75BEA26A311CE9E06519690C6012BDC3" xlink:to="loc_us-gaap_NetIncomeLoss_F393ECF3F87E20B1766A690C60142FED" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_F483EB8C5F02BB3F4C21690C60140A8D" xlink:type="locator" />
    <definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_75BEA26A311CE9E06519690C6012BDC3" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_F483EB8C5F02BB3F4C21690C60140A8D" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_4A19F19C68F13E7C9C92690C60147975" xlink:type="locator" />
    <definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_75BEA26A311CE9E06519690C6012BDC3" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_4A19F19C68F13E7C9C92690C60147975" xlink:type="arc" />
  </definitionLink>
  <definitionLink xlink:role="http://www.dycomind.com/role/SupplementalConsolidatingFinancialStatementsTables" xlink:type="extended" />
</linkbase>
