<?xml version="1.0" encoding="US-ASCII"?>
<!--XBRL Document Created with Wdesk from Workiva-->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="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">
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/BasisOfPresentation" xlink:href="htld-20170331.xsd#BasisOfPresentation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/BasisOfPresentationBasisOfPresentationPolicies" xlink:href="htld-20170331.xsd#BasisOfPresentationBasisOfPresentationPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/CashAndCashEquivalents" xlink:href="htld-20170331.xsd#CashAndCashEquivalents" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/CashAndCashEquivalentsDetails" xlink:href="htld-20170331.xsd#CashAndCashEquivalentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/CommitmentsAndContingencies" xlink:href="htld-20170331.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/CommitmentsAndContingenciesDetails" xlink:href="htld-20170331.xsd#CommitmentsAndContingenciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/ConsolidatedBalanceSheets" xlink:href="htld-20170331.xsd#ConsolidatedBalanceSheets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/ConsolidatedBalanceSheetsConsolidatedBalanceSheetsParentheticals" xlink:href="htld-20170331.xsd#ConsolidatedBalanceSheetsConsolidatedBalanceSheetsParentheticals" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/ConsolidatedStatementOfStockholdersEquityParentheticals" xlink:href="htld-20170331.xsd#ConsolidatedStatementOfStockholdersEquityParentheticals" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="htld-20170331.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:href="htld-20170331.xsd#ConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:href="htld-20170331.xsd#ConsolidatedStatementsOfStockholdersEquity" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/DocumentAndEntityInformation" xlink:href="htld-20170331.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/EarningsPerShare" xlink:href="htld-20170331.xsd#EarningsPerShare" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/EarningsPerShareDetails" xlink:href="htld-20170331.xsd#EarningsPerShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/EarningsPerShareTables" xlink:href="htld-20170331.xsd#EarningsPerShareTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/Equity" xlink:href="htld-20170331.xsd#Equity" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/EquityDetails" xlink:href="htld-20170331.xsd#EquityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/IncomeTaxes" xlink:href="htld-20170331.xsd#IncomeTaxes" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/IncomeTaxesDetails" xlink:href="htld-20170331.xsd#IncomeTaxesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/IncomeTaxesTables" xlink:href="htld-20170331.xsd#IncomeTaxesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/LongTermDebt" xlink:href="htld-20170331.xsd#LongTermDebt" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/LongTermDebtDetails" xlink:href="htld-20170331.xsd#LongTermDebtDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/OperatingLeases" xlink:href="htld-20170331.xsd#OperatingLeases" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/OperatingLeasesDetails" xlink:href="htld-20170331.xsd#OperatingLeasesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/OtherIntangibleNetAndGoodwill" xlink:href="htld-20170331.xsd#OtherIntangibleNetAndGoodwill" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/OtherIntangibleNetAndGoodwillChangesCarryingAmountOfGoodwillDetails" xlink:href="htld-20170331.xsd#OtherIntangibleNetAndGoodwillChangesCarryingAmountOfGoodwillDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/OtherIntangibleNetAndGoodwillDetails" xlink:href="htld-20170331.xsd#OtherIntangibleNetAndGoodwillDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/OtherIntangibleNetAndGoodwillTables" xlink:href="htld-20170331.xsd#OtherIntangibleNetAndGoodwillTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/PrepaidTiresPropertyEquipmentAndDepreciation" xlink:href="htld-20170331.xsd#PrepaidTiresPropertyEquipmentAndDepreciation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/PrepaidTiresPropertyEquipmentAndDepreciationDetails" xlink:href="htld-20170331.xsd#PrepaidTiresPropertyEquipmentAndDepreciationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/RelatedParty" xlink:href="htld-20170331.xsd#RelatedParty" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/RelatedPartyDetails" xlink:href="htld-20170331.xsd#RelatedPartyDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/RelatedPartyTables" xlink:href="htld-20170331.xsd#RelatedPartyTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/SegmentInformation" xlink:href="htld-20170331.xsd#SegmentInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/SegmentInformationDetails" xlink:href="htld-20170331.xsd#SegmentInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/StockBasedCompensation" xlink:href="htld-20170331.xsd#StockBasedCompensation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/StockBasedCompensationDetails" xlink:href="htld-20170331.xsd#StockBasedCompensationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/StockBasedCompensationTables" xlink:href="htld-20170331.xsd#StockBasedCompensationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/SubsequentEvents" xlink:href="htld-20170331.xsd#SubsequentEvents" xlink:type="simple" />
  <link:roleRef roleURI="http://www.heartlandexpress.com/role/UseOfEstimates" xlink:href="htld-20170331.xsd#UseOfEstimates" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <link: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" />
  <link: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" />
  <link: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" />
  <link: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" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/BasisOfPresentation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/BasisOfPresentationBasisOfPresentationPolicies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/CashAndCashEquivalents" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/CashAndCashEquivalentsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/CommitmentsAndContingencies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/CommitmentsAndContingenciesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/ConsolidatedBalanceSheets" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/ConsolidatedBalanceSheetsConsolidatedBalanceSheetsParentheticals" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/ConsolidatedStatementOfStockholdersEquityParentheticals" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_0080D75B585B26CA4CBEA5B5BA071B1D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_F7325C5732CFD1708B5FA5B5BA06BA74" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_0080D75B585B26CA4CBEA5B5BA071B1D" xlink:to="loc_us-gaap_StatementTable_F7325C5732CFD1708B5FA5B5BA06BA74" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_37167CE835ACA2E56CA4A5B5BA0640CA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_F7325C5732CFD1708B5FA5B5BA06BA74" xlink:to="loc_us-gaap_StatementScenarioAxis_37167CE835ACA2E56CA4A5B5BA0640CA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_029633A9C5E3215F3EEFA5B5BA072C46_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_37167CE835ACA2E56CA4A5B5BA0640CA" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_029633A9C5E3215F3EEFA5B5BA072C46_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_029633A9C5E3215F3EEFA5B5BA072C46" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_37167CE835ACA2E56CA4A5B5BA0640CA" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_029633A9C5E3215F3EEFA5B5BA072C46" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockDividendsPerShareDeclared" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_F7B12506812A4F376BADA5B5BA070762" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0080D75B585B26CA4CBEA5B5BA071B1D" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_F7B12506812A4F376BADA5B5BA070762" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_DF2EB352DBB9EA67A5CAF34ED7E5B572" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_510A4C41FDC1DAADBDAAF34ED7E45BEE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_DF2EB352DBB9EA67A5CAF34ED7E5B572" xlink:to="loc_us-gaap_StatementTable_510A4C41FDC1DAADBDAAF34ED7E45BEE" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_0204733222FF5A8C47A5F34ED7E4E17D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_510A4C41FDC1DAADBDAAF34ED7E45BEE" xlink:to="loc_us-gaap_StatementScenarioAxis_0204733222FF5A8C47A5F34ED7E4E17D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_D606FC2D7678B70E293EF34ED7E49E09_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_0204733222FF5A8C47A5F34ED7E4E17D" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_D606FC2D7678B70E293EF34ED7E49E09_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_D606FC2D7678B70E293EF34ED7E49E09" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_0204733222FF5A8C47A5F34ED7E4E17D" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_D606FC2D7678B70E293EF34ED7E49E09" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_79DCAB62A57B796806BAC9F271F3432A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_0269126EDE315527C1BFC9F271F39F53" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_79DCAB62A57B796806BAC9F271F3432A" xlink:to="loc_us-gaap_StatementTable_0269126EDE315527C1BFC9F271F39F53" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_C6C64DBF7EAF6112F4A3C9F271F3C537" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_0269126EDE315527C1BFC9F271F39F53" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_C6C64DBF7EAF6112F4A3C9F271F3C537" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_5C8D4874A98FB3B915E8C9F271F3BE11_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_C6C64DBF7EAF6112F4A3C9F271F3C537" xlink:to="loc_us-gaap_EquityComponentDomain_5C8D4874A98FB3B915E8C9F271F3BE11_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_5C8D4874A98FB3B915E8C9F271F3BE11" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_C6C64DBF7EAF6112F4A3C9F271F3C537" xlink:to="loc_us-gaap_EquityComponentDomain_5C8D4874A98FB3B915E8C9F271F3BE11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_406AFEB003EB3E119DBEC9F271F3CD07" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5C8D4874A98FB3B915E8C9F271F3BE11" xlink:to="loc_us-gaap_CommonStockMember_406AFEB003EB3E119DBEC9F271F3CD07" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_AA8552EFDA12BF0BDD6AC9F271F3CD74" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5C8D4874A98FB3B915E8C9F271F3BE11" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_AA8552EFDA12BF0BDD6AC9F271F3CD74" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_292CB1A66CCD87379FD1C9F271F3D94E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5C8D4874A98FB3B915E8C9F271F3BE11" xlink:to="loc_us-gaap_RetainedEarningsMember_292CB1A66CCD87379FD1C9F271F3D94E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockMember" xlink:label="loc_us-gaap_TreasuryStockMember_E92BACE96FE66FDDFD29C9F271F34451" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5C8D4874A98FB3B915E8C9F271F3BE11" xlink:to="loc_us-gaap_TreasuryStockMember_E92BACE96FE66FDDFD29C9F271F34451" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_9A72D77ACE358A320481C9F271F34B7E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_79DCAB62A57B796806BAC9F271F3432A" xlink:to="loc_us-gaap_StockholdersEquity_9A72D77ACE358A320481C9F271F34B7E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_B57E273F963A511EE289C9F271F32840" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_79DCAB62A57B796806BAC9F271F3432A" xlink:to="loc_us-gaap_NetIncomeLoss_B57E273F963A511EE289C9F271F32840" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DividendsCommonStock" xlink:label="loc_us-gaap_DividendsCommonStock_024CA77748FC807A228FC9F271F41082" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_79DCAB62A57B796806BAC9F271F3432A" xlink:to="loc_us-gaap_DividendsCommonStock_024CA77748FC807A228FC9F271F41082" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_6814B3CE6D9E9ACBE2BDC9F271F47F97" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_79DCAB62A57B796806BAC9F271F3432A" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_6814B3CE6D9E9ACBE2BDC9F271F47F97" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_D75016B3BD96E9C9F0A0C9F271F45F22" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_79DCAB62A57B796806BAC9F271F3432A" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_D75016B3BD96E9C9F0A0C9F271F45F22" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/DocumentAndEntityInformation" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentInformationLineItems" xlink:label="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentInformationTable" xlink:label="loc_dei_DocumentInformationTable_600E0CA9C8CE50BFB8C86FA252A37AD3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:to="loc_dei_DocumentInformationTable_600E0CA9C8CE50BFB8C86FA252A37AD3" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentInformationDocumentAxis" xlink:label="loc_dei_DocumentInformationDocumentAxis_BF7DB2A1EB7B5760B4BCC0234F3C832E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_600E0CA9C8CE50BFB8C86FA252A37AD3" xlink:to="loc_dei_DocumentInformationDocumentAxis_BF7DB2A1EB7B5760B4BCC0234F3C832E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentDomain" xlink:label="loc_dei_DocumentDomain_05CEBC74A67EBAF6BAB96862673AF131_33E66F728EA457A7A6A88F9261FC83C2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_DocumentInformationDocumentAxis_BF7DB2A1EB7B5760B4BCC0234F3C832E" xlink:to="loc_dei_DocumentDomain_05CEBC74A67EBAF6BAB96862673AF131_33E66F728EA457A7A6A88F9261FC83C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentDomain" xlink:label="loc_dei_DocumentDomain_CA34F1EC4A8351A6BFC372A19CEA4124" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_DocumentInformationDocumentAxis_BF7DB2A1EB7B5760B4BCC0234F3C832E" xlink:to="loc_dei_DocumentDomain_CA34F1EC4A8351A6BFC372A19CEA4124" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityRegistrantName" xlink:label="loc_dei_EntityRegistrantName_66D18508AB1C50F79C729DC22BBDF16B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:to="loc_dei_EntityRegistrantName_66D18508AB1C50F79C729DC22BBDF16B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="loc_dei_EntityCentralIndexKey_AEFDF4F1557F567EAFCD7B449258F9EE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:to="loc_dei_EntityCentralIndexKey_AEFDF4F1557F567EAFCD7B449258F9EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentType" xlink:label="loc_dei_DocumentType_4308F0F3BC6B5DB3B72D33E884965781" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:to="loc_dei_DocumentType_4308F0F3BC6B5DB3B72D33E884965781" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="loc_dei_DocumentPeriodEndDate_306617FE13F4529E98CB14102B1FE251" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:to="loc_dei_DocumentPeriodEndDate_306617FE13F4529E98CB14102B1FE251" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="loc_dei_DocumentFiscalYearFocus_1795D3FDEC0B50F098F9C535FA8DC6E0" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:to="loc_dei_DocumentFiscalYearFocus_1795D3FDEC0B50F098F9C535FA8DC6E0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="loc_dei_DocumentFiscalPeriodFocus_2C9A93DB7F715FF98276AF521779A085" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:to="loc_dei_DocumentFiscalPeriodFocus_2C9A93DB7F715FF98276AF521779A085" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="loc_dei_CurrentFiscalYearEndDate_A407B815E2485B3AA14FF8A767A29948" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:to="loc_dei_CurrentFiscalYearEndDate_A407B815E2485B3AA14FF8A767A29948" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_AmendmentFlag" xlink:label="loc_dei_AmendmentFlag_7F62AB1B7EB25450A4EC1BB4F7998A60" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:to="loc_dei_AmendmentFlag_7F62AB1B7EB25450A4EC1BB4F7998A60" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityFilerCategory" xlink:label="loc_dei_EntityFilerCategory_EBF467EC37285BE8862CB54BCE04E2AC" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:to="loc_dei_EntityFilerCategory_EBF467EC37285BE8862CB54BCE04E2AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_B92CA7626AEB580CB9E898A5805E0A6D" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_4A4FED9D269B5A309B667332240C506C" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_B92CA7626AEB580CB9E898A5805E0A6D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/EarningsPerShare" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/EarningsPerShareDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/EarningsPerShareTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/Equity" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/EquityDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/IncomeTaxes" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/IncomeTaxesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_592BADF2B71A7FA69830EEEF51498DB8" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_63F2E11386A8D0EA3105EEEF5148FFB8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_592BADF2B71A7FA69830EEEF51498DB8" xlink:to="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_63F2E11386A8D0EA3105EEEF5148FFB8" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_B4FDBA80DD035B6C51DFEEEF51490201" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_63F2E11386A8D0EA3105EEEF5148FFB8" xlink:to="loc_us-gaap_RangeAxis_B4FDBA80DD035B6C51DFEEEF51490201" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_D24D67A127C1198ED177EEEF51498A3F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_B4FDBA80DD035B6C51DFEEEF51490201" xlink:to="loc_us-gaap_RangeMember_D24D67A127C1198ED177EEEF51498A3F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_D24D67A127C1198ED177EEEF51498A3F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_B4FDBA80DD035B6C51DFEEEF51490201" xlink:to="loc_us-gaap_RangeMember_D24D67A127C1198ED177EEEF51498A3F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_B37FD6D74B11A5A46492EEEF514977D1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_D24D67A127C1198ED177EEEF51498A3F" xlink:to="loc_us-gaap_MinimumMember_B37FD6D74B11A5A46492EEEF514977D1" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_UnrecognizedTaxBenefitsAxis" xlink:label="loc_htld_UnrecognizedTaxBenefitsAxis_8C9E0E020A67C60E44ACEEEF514940E2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_63F2E11386A8D0EA3105EEEF5148FFB8" xlink:to="loc_htld_UnrecognizedTaxBenefitsAxis_8C9E0E020A67C60E44ACEEEF514940E2" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_PortionOfTaxBenefitRecordedPositionDomain" xlink:label="loc_htld_PortionOfTaxBenefitRecordedPositionDomain_E31FFF1B0D046705B86AEEEF5149D139_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_htld_UnrecognizedTaxBenefitsAxis_8C9E0E020A67C60E44ACEEEF514940E2" xlink:to="loc_htld_PortionOfTaxBenefitRecordedPositionDomain_E31FFF1B0D046705B86AEEEF5149D139_default" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_PortionOfTaxBenefitRecordedPositionDomain" xlink:label="loc_htld_PortionOfTaxBenefitRecordedPositionDomain_E31FFF1B0D046705B86AEEEF5149D139" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_htld_UnrecognizedTaxBenefitsAxis_8C9E0E020A67C60E44ACEEEF514940E2" xlink:to="loc_htld_PortionOfTaxBenefitRecordedPositionDomain_E31FFF1B0D046705B86AEEEF5149D139" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_6D5CA7CB18487DEB6005EEEF5149882C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htld_PortionOfTaxBenefitRecordedPositionDomain_E31FFF1B0D046705B86AEEEF5149D139" xlink:to="loc_us-gaap_MaximumMember_6D5CA7CB18487DEB6005EEEF5149882C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit_4D49BD16363C19FB02C1EEEF5149AA44" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_592BADF2B71A7FA69830EEEF51498DB8" xlink:to="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit_4D49BD16363C19FB02C1EEEF5149AA44" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/IncomeTaxesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/LongTermDebt" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/LongTermDebtDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_744E582AF3FD6115CE44EA1D6824142C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_F1AED4FD10CC895D02FCEA1D6823036A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_744E582AF3FD6115CE44EA1D6824142C" xlink:to="loc_us-gaap_DebtInstrumentTable_F1AED4FD10CC895D02FCEA1D6823036A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_6B953EAAD6D7EBEB3C7DEA1D6824C3A6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_F1AED4FD10CC895D02FCEA1D6823036A" xlink:to="loc_us-gaap_VariableRateAxis_6B953EAAD6D7EBEB3C7DEA1D6824C3A6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_C9ECE7A3A2F64BCADF9AEA1D682487D5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_6B953EAAD6D7EBEB3C7DEA1D6824C3A6" xlink:to="loc_us-gaap_VariableRateDomain_C9ECE7A3A2F64BCADF9AEA1D682487D5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_C9ECE7A3A2F64BCADF9AEA1D682487D5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_6B953EAAD6D7EBEB3C7DEA1D6824C3A6" xlink:to="loc_us-gaap_VariableRateDomain_C9ECE7A3A2F64BCADF9AEA1D682487D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_48247B7B421B218F7DB4EA1D6824E074" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_C9ECE7A3A2F64BCADF9AEA1D682487D5" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_48247B7B421B218F7DB4EA1D6824E074" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PrimeRateMember" xlink:label="loc_us-gaap_PrimeRateMember_1AEB3B8AB6A871E98C3AEA1D6824BBEE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_C9ECE7A3A2F64BCADF9AEA1D682487D5" xlink:to="loc_us-gaap_PrimeRateMember_1AEB3B8AB6A871E98C3AEA1D6824BBEE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_941DE4AAAE11941881C5EA1D68246CF9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_744E582AF3FD6115CE44EA1D6824142C" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_941DE4AAAE11941881C5EA1D68246CF9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_0ACE817703A786B0F7ABEA1D6824E3C1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_744E582AF3FD6115CE44EA1D6824142C" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_0ACE817703A786B0F7ABEA1D6824E3C1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_B41E09A36A665FB519CFEA1D68242807" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_744E582AF3FD6115CE44EA1D6824142C" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_B41E09A36A665FB519CFEA1D68242807" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_DebtInstrumentCovenantLeverageRatio" xlink:label="loc_htld_DebtInstrumentCovenantLeverageRatio_F854E4967EFC0D73BE36EA1D68241D18" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_744E582AF3FD6115CE44EA1D6824142C" xlink:to="loc_htld_DebtInstrumentCovenantLeverageRatio_F854E4967EFC0D73BE36EA1D68241D18" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_DebtCovenantMinimumNetIncomeRequirement" xlink:label="loc_htld_DebtCovenantMinimumNetIncomeRequirement_9F79B0CAAA07CEB91A6AEA1D68255FCA" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_744E582AF3FD6115CE44EA1D6824142C" xlink:to="loc_htld_DebtCovenantMinimumNetIncomeRequirement_9F79B0CAAA07CEB91A6AEA1D68255FCA" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_DebtCovenantMinimumTangibleNetWorth" xlink:label="loc_htld_DebtCovenantMinimumTangibleNetWorth_AC05B1A13293F8DE9DA4EA4A228BE52E" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_744E582AF3FD6115CE44EA1D6824142C" xlink:to="loc_htld_DebtCovenantMinimumTangibleNetWorth_AC05B1A13293F8DE9DA4EA4A228BE52E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_BEB892BE2291B9E92E41EA1DFCD5A40F" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_744E582AF3FD6115CE44EA1D6824142C" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_BEB892BE2291B9E92E41EA1DFCD5A40F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_E4F9E5381F569AEFE668EA1F059674CD" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_744E582AF3FD6115CE44EA1D6824142C" xlink:to="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_E4F9E5381F569AEFE668EA1F059674CD" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/OperatingLeases" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/OperatingLeasesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OperatingLeasedAssetsLineItems" xlink:label="loc_us-gaap_OperatingLeasedAssetsLineItems_1A41E1D976BDA7AD332AEDA86DFC0920" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfOperatingLeasedAssetsTable" xlink:label="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_EA50ED6D263A2979D2E8EDA86DFB53D3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_1A41E1D976BDA7AD332AEDA86DFC0920" xlink:to="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_EA50ED6D263A2979D2E8EDA86DFB53D3" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_C56BA539A38AFEA1C117EDA86DFBDB50" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_EA50ED6D263A2979D2E8EDA86DFB53D3" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_C56BA539A38AFEA1C117EDA86DFBDB50" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FC521215FBD5417E4E81EDA86DFBECE0_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_C56BA539A38AFEA1C117EDA86DFBDB50" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FC521215FBD5417E4E81EDA86DFBECE0_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FC521215FBD5417E4E81EDA86DFBECE0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_C56BA539A38AFEA1C117EDA86DFBDB50" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FC521215FBD5417E4E81EDA86DFBECE0" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_TractorsMember" xlink:label="loc_htld_TractorsMember_C90292475E7B6AA66D9FEDA86DFB1C8E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FC521215FBD5417E4E81EDA86DFBECE0" xlink:to="loc_htld_TractorsMember_C90292475E7B6AA66D9FEDA86DFB1C8E" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_TrailersMember" xlink:label="loc_htld_TrailersMember_4FE9028B80F5A4EC7F66EDA86DFB9E76" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FC521215FBD5417E4E81EDA86DFBECE0" xlink:to="loc_htld_TrailersMember_4FE9028B80F5A4EC7F66EDA86DFB9E76" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_2B18D18FA66EB75A4F83EDA86DFB6F49" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_EA50ED6D263A2979D2E8EDA86DFB53D3" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_2B18D18FA66EB75A4F83EDA86DFB6F49" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_64E50A80E0A45D8DF273EDA86DFBE822_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2B18D18FA66EB75A4F83EDA86DFB6F49" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_64E50A80E0A45D8DF273EDA86DFBE822_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_64E50A80E0A45D8DF273EDA86DFBE822" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2B18D18FA66EB75A4F83EDA86DFB6F49" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_64E50A80E0A45D8DF273EDA86DFBE822" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_2165E89E607ADC1F7A1AEDA86DFB9CA0" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_EA50ED6D263A2979D2E8EDA86DFB53D3" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_2165E89E607ADC1F7A1AEDA86DFB9CA0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_A930EA6C3740D98B2E24EDA86DFBBF18_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_2165E89E607ADC1F7A1AEDA86DFB9CA0" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_A930EA6C3740D98B2E24EDA86DFBBF18_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_A930EA6C3740D98B2E24EDA86DFBBF18" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_2165E89E607ADC1F7A1AEDA86DFB9CA0" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_A930EA6C3740D98B2E24EDA86DFBBF18" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_TerminalFacilitiesMember" xlink:label="loc_htld_TerminalFacilitiesMember_845FA33DA7CD799F8D2FEDA86DFBD319" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_A930EA6C3740D98B2E24EDA86DFBBF18" xlink:to="loc_htld_TerminalFacilitiesMember_845FA33DA7CD799F8D2FEDA86DFBD319" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LeaseArrangementTypeAxis" xlink:label="loc_us-gaap_LeaseArrangementTypeAxis_16EC4749C13C1BCE2470EDA86DFBD5EA" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_EA50ED6D263A2979D2E8EDA86DFB53D3" xlink:to="loc_us-gaap_LeaseArrangementTypeAxis_16EC4749C13C1BCE2470EDA86DFBD5EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LeaseArrangementTypeDomain" xlink:label="loc_us-gaap_LeaseArrangementTypeDomain_CCC23FCC36F90EDDD5D5EDA86DFB828E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LeaseArrangementTypeAxis_16EC4749C13C1BCE2470EDA86DFBD5EA" xlink:to="loc_us-gaap_LeaseArrangementTypeDomain_CCC23FCC36F90EDDD5D5EDA86DFB828E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LeaseArrangementTypeDomain" xlink:label="loc_us-gaap_LeaseArrangementTypeDomain_CCC23FCC36F90EDDD5D5EDA86DFB828E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LeaseArrangementTypeAxis_16EC4749C13C1BCE2470EDA86DFBD5EA" xlink:to="loc_us-gaap_LeaseArrangementTypeDomain_CCC23FCC36F90EDDD5D5EDA86DFB828E" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_RelatedPartyMember" xlink:label="loc_htld_RelatedPartyMember_1D66F24D5C3BDBA99AE3EDA86DFC7EA3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LeaseArrangementTypeDomain_CCC23FCC36F90EDDD5D5EDA86DFB828E" xlink:to="loc_htld_RelatedPartyMember_1D66F24D5C3BDBA99AE3EDA86DFC7EA3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty" xlink:label="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_70D7F932C098F724197DEDA86DFC9173" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_1A41E1D976BDA7AD332AEDA86DFC0920" xlink:to="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_70D7F932C098F724197DEDA86DFC9173" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_B794CB482D6001A2A0E8EDA86DFCD46E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_1A41E1D976BDA7AD332AEDA86DFC0920" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_B794CB482D6001A2A0E8EDA86DFCD46E" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_Relatedpartypaymentforterminalpurchase" xlink:label="loc_htld_Relatedpartypaymentforterminalpurchase_571D6782FAB91DCFC6F8EDA86DFCBA1B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_1A41E1D976BDA7AD332AEDA86DFC0920" xlink:to="loc_htld_Relatedpartypaymentforterminalpurchase_571D6782FAB91DCFC6F8EDA86DFCBA1B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/OtherIntangibleNetAndGoodwill" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/OtherIntangibleNetAndGoodwillChangesCarryingAmountOfGoodwillDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/OtherIntangibleNetAndGoodwillDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2986B5B7B09914CBC737EA3113B59744" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_E89FFA13F8A3C27B7BFAEA3113A51B3C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2986B5B7B09914CBC737EA3113B59744" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_E89FFA13F8A3C27B7BFAEA3113A51B3C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_970A44D821A039B3E780EA3113A56E74" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_E89FFA13F8A3C27B7BFAEA3113A51B3C" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_970A44D821A039B3E780EA3113A56E74" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0AAA941535257B01BCBBEA3113A57239_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_970A44D821A039B3E780EA3113A56E74" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0AAA941535257B01BCBBEA3113A57239_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0AAA941535257B01BCBBEA3113A57239" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_970A44D821A039B3E780EA3113A56E74" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0AAA941535257B01BCBBEA3113A57239" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_ECEA40EDD6968993622BEA3113A5674F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0AAA941535257B01BCBBEA3113A57239" xlink:to="loc_us-gaap_CustomerRelationshipsMember_ECEA40EDD6968993622BEA3113A5674F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="loc_us-gaap_TradeNamesMember_0823917A81D9FCA59DC5EA3113A5AC8E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0AAA941535257B01BCBBEA3113A57239" xlink:to="loc_us-gaap_TradeNamesMember_0823917A81D9FCA59DC5EA3113A5AC8E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NoncompeteAgreementsMember" xlink:label="loc_us-gaap_NoncompeteAgreementsMember_AB8E002C5A41DA432565EA3113B5C495" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0AAA941535257B01BCBBEA3113A57239" xlink:to="loc_us-gaap_NoncompeteAgreementsMember_AB8E002C5A41DA432565EA3113B5C495" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RealEstateMember" xlink:label="loc_us-gaap_RealEstateMember_99131F9A959F947A1823EA3113B5DF50" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0AAA941535257B01BCBBEA3113A57239" xlink:to="loc_us-gaap_RealEstateMember_99131F9A959F947A1823EA3113B5DF50" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_558FA09EE6BC5CE3394AEA399D5C3D12" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2986B5B7B09914CBC737EA3113B59744" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_558FA09EE6BC5CE3394AEA399D5C3D12" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_CE05ABCECC489E7EEF11EA3113B56391" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2986B5B7B09914CBC737EA3113B59744" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_CE05ABCECC489E7EEF11EA3113B56391" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_D321A7A50B2B8D1DBF0AEA3113B5E605" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2986B5B7B09914CBC737EA3113B59744" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_D321A7A50B2B8D1DBF0AEA3113B5E605" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_478DBAB56FEA5EEE130EEA3113B5E0B8" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2986B5B7B09914CBC737EA3113B59744" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_478DBAB56FEA5EEE130EEA3113B5E0B8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_AB05FBAC2AEEFFC29903EA3113B5BDE9" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_2986B5B7B09914CBC737EA3113B59744" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_AB05FBAC2AEEFFC29903EA3113B5BDE9" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/OtherIntangibleNetAndGoodwillTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/PrepaidTiresPropertyEquipmentAndDepreciation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/PrepaidTiresPropertyEquipmentAndDepreciationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2BF250F8C5BF54E49E70F7099F3E7423" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_F0B3866971065F8B8D138A925BE63F73" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2BF250F8C5BF54E49E70F7099F3E7423" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_F0B3866971065F8B8D138A925BE63F73" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="htld-20170331.xsd#htld_FinancialStatementLocationAxis" xlink:label="loc_htld_FinancialStatementLocationAxis_385B6EB6E56054959F56C11B7F83F940" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_F0B3866971065F8B8D138A925BE63F73" xlink:to="loc_htld_FinancialStatementLocationAxis_385B6EB6E56054959F56C11B7F83F940" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_FinancialStatementLocationDomain" xlink:label="loc_htld_FinancialStatementLocationDomain_82A77F7B16C0DC676C7E3C183A1C4B3F_33E66F728EA457A7A6A88F9261FC83C2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_htld_FinancialStatementLocationAxis_385B6EB6E56054959F56C11B7F83F940" xlink:to="loc_htld_FinancialStatementLocationDomain_82A77F7B16C0DC676C7E3C183A1C4B3F_33E66F728EA457A7A6A88F9261FC83C2" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_FinancialStatementLocationDomain" xlink:label="loc_htld_FinancialStatementLocationDomain_6C4689022CE85E39A1505C8B3D526701" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_htld_FinancialStatementLocationAxis_385B6EB6E56054959F56C11B7F83F940" xlink:to="loc_htld_FinancialStatementLocationDomain_6C4689022CE85E39A1505C8B3D526701" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_CommunicationsAndUtilitiesExpenseMember" xlink:label="loc_htld_CommunicationsAndUtilitiesExpenseMember_0DEE53ED04055755A93BC779A58B1456" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htld_FinancialStatementLocationDomain_6C4689022CE85E39A1505C8B3D526701" xlink:to="loc_htld_CommunicationsAndUtilitiesExpenseMember_0DEE53ED04055755A93BC779A58B1456" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3275D5660FD3552FA7D0F3390D2708B9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_F0B3866971065F8B8D138A925BE63F73" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3275D5660FD3552FA7D0F3390D2708B9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_01A8C411C87416A37A833C183A1C386E_33E66F728EA457A7A6A88F9261FC83C2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3275D5660FD3552FA7D0F3390D2708B9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_01A8C411C87416A37A833C183A1C386E_33E66F728EA457A7A6A88F9261FC83C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_F00DD38BC1F7562EBD904E2AC6ADD4A6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3275D5660FD3552FA7D0F3390D2708B9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_F00DD38BC1F7562EBD904E2AC6ADD4A6" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_TractorsMember" xlink:label="loc_htld_TractorsMember_485A7E68FB0953A097036871DB970739" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_F00DD38BC1F7562EBD904E2AC6ADD4A6" xlink:to="loc_htld_TractorsMember_485A7E68FB0953A097036871DB970739" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_TrailersMember" xlink:label="loc_htld_TrailersMember_189E047EF14555AEA7E82A4ABCA1C174" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_F00DD38BC1F7562EBD904E2AC6ADD4A6" xlink:to="loc_htld_TrailersMember_189E047EF14555AEA7E82A4ABCA1C174" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_AmortizationPeriodOfTires" xlink:label="loc_htld_AmortizationPeriodOfTires_BEFDE01B07555D25B4A8385222857C48" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2BF250F8C5BF54E49E70F7099F3E7423" xlink:to="loc_htld_AmortizationPeriodOfTires_BEFDE01B07555D25B4A8385222857C48" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Depreciation" xlink:label="loc_us-gaap_Depreciation_50ADCFEA123054D5A1AEA4DD77DA1F20" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2BF250F8C5BF54E49E70F7099F3E7423" xlink:to="loc_us-gaap_Depreciation_50ADCFEA123054D5A1AEA4DD77DA1F20" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentSalvageValue" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentSalvageValue_70C6F263C9E45941BF4B1E7256A54F41" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2BF250F8C5BF54E49E70F7099F3E7423" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentSalvageValue_70C6F263C9E45941BF4B1E7256A54F41" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/RelatedParty" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/RelatedPartyDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_55FD4B23FD6CFF64C4EFEDA86DF2216B" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_A5F5B60D5729B7282968EDA86DF2B1DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_55FD4B23FD6CFF64C4EFEDA86DF2216B" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_A5F5B60D5729B7282968EDA86DF2B1DE" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_72D117643E1D5EAF0856EDA86DF2F062" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_A5F5B60D5729B7282968EDA86DF2B1DE" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_72D117643E1D5EAF0856EDA86DF2F062" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3EDCF0EEDC8FBB454491EDA86DF2FCE4_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_72D117643E1D5EAF0856EDA86DF2F062" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3EDCF0EEDC8FBB454491EDA86DF2FCE4_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3EDCF0EEDC8FBB454491EDA86DF2FCE4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_72D117643E1D5EAF0856EDA86DF2F062" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3EDCF0EEDC8FBB454491EDA86DF2FCE4" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_TractorsMember" xlink:label="loc_htld_TractorsMember_EB9FE374C60C95578AD5EDA86DF2C3A9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3EDCF0EEDC8FBB454491EDA86DF2FCE4" xlink:to="loc_htld_TractorsMember_EB9FE374C60C95578AD5EDA86DF2C3A9" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_TrailersMember" xlink:label="loc_htld_TrailersMember_8A4C26CBE0E58B974EA5EDA86DF2B506" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3EDCF0EEDC8FBB454491EDA86DF2FCE4" xlink:to="loc_htld_TrailersMember_8A4C26CBE0E58B974EA5EDA86DF2B506" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_41AC21A329D73F73C926EDA86DF2E96D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_A5F5B60D5729B7282968EDA86DF2B1DE" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_41AC21A329D73F73C926EDA86DF2E96D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_167D31B49126883F7713EDA86DF2FDA7_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_41AC21A329D73F73C926EDA86DF2E96D" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_167D31B49126883F7713EDA86DF2FDA7_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_167D31B49126883F7713EDA86DF2FDA7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_41AC21A329D73F73C926EDA86DF2E96D" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_167D31B49126883F7713EDA86DF2FDA7" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_TerminalFacilitiesMember" xlink:label="loc_htld_TerminalFacilitiesMember_8269D4B8CDAEC9CB00ECEDA86DF28759" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_167D31B49126883F7713EDA86DF2FDA7" xlink:to="loc_htld_TerminalFacilitiesMember_8269D4B8CDAEC9CB00ECEDA86DF28759" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LeaseArrangementTypeAxis" xlink:label="loc_us-gaap_LeaseArrangementTypeAxis_007E6BDC234504BCCBE7EDA86DF23C45" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_A5F5B60D5729B7282968EDA86DF2B1DE" xlink:to="loc_us-gaap_LeaseArrangementTypeAxis_007E6BDC234504BCCBE7EDA86DF23C45" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LeaseArrangementTypeDomain" xlink:label="loc_us-gaap_LeaseArrangementTypeDomain_285B66627607B693B452EDA86DF2CD1E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LeaseArrangementTypeAxis_007E6BDC234504BCCBE7EDA86DF23C45" xlink:to="loc_us-gaap_LeaseArrangementTypeDomain_285B66627607B693B452EDA86DF2CD1E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LeaseArrangementTypeDomain" xlink:label="loc_us-gaap_LeaseArrangementTypeDomain_285B66627607B693B452EDA86DF2CD1E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LeaseArrangementTypeAxis_007E6BDC234504BCCBE7EDA86DF23C45" xlink:to="loc_us-gaap_LeaseArrangementTypeDomain_285B66627607B693B452EDA86DF2CD1E" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_RelatedPartyMember" xlink:label="loc_htld_RelatedPartyMember_8902E5F38B55C3366A8CEDA86DF2F8EF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LeaseArrangementTypeDomain_285B66627607B693B452EDA86DF2CD1E" xlink:to="loc_htld_RelatedPartyMember_8902E5F38B55C3366A8CEDA86DF2F8EF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LeaseAndRentalExpense" xlink:label="loc_us-gaap_LeaseAndRentalExpense_93D526D9563A5B027B5BEDD02EABC931" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_55FD4B23FD6CFF64C4EFEDA86DF2216B" xlink:to="loc_us-gaap_LeaseAndRentalExpense_93D526D9563A5B027B5BEDD02EABC931" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_FairValueOfRevenueEquipmentTraded" xlink:label="loc_htld_FairValueOfRevenueEquipmentTraded_3FD46BB9204204520D41EDA86DF3344C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_55FD4B23FD6CFF64C4EFEDA86DF2216B" xlink:to="loc_htld_FairValueOfRevenueEquipmentTraded_3FD46BB9204204520D41EDA86DF3344C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DueToRelatedPartiesCurrent" xlink:label="loc_us-gaap_DueToRelatedPartiesCurrent_F7AC44271D6ABEE3E575EDA86DF3613E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_55FD4B23FD6CFF64C4EFEDA86DF2216B" xlink:to="loc_us-gaap_DueToRelatedPartiesCurrent_F7AC44271D6ABEE3E575EDA86DF3613E" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_Relatedpartypaymentforterminalpurchase" xlink:label="loc_htld_Relatedpartypaymentforterminalpurchase_80B260398F285223F8B3EDA86DF33DAF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_55FD4B23FD6CFF64C4EFEDA86DF2216B" xlink:to="loc_htld_Relatedpartypaymentforterminalpurchase_80B260398F285223F8B3EDA86DF33DAF" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_Paymentsforpartsandservices" xlink:label="loc_htld_Paymentsforpartsandservices_B86E63FF36B0B89419B3EDA86DF3FC83" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_55FD4B23FD6CFF64C4EFEDA86DF2216B" xlink:to="loc_htld_Paymentsforpartsandservices_B86E63FF36B0B89419B3EDA86DF3FC83" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/RelatedPartyTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/SegmentInformation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/SegmentInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_521BEBCDB936378BAE64CB40A17540AE" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_11AB74198E98BAEC94A3CB40A1751F82" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_521BEBCDB936378BAE64CB40A17540AE" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_11AB74198E98BAEC94A3CB40A1751F82" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConsolidationItemsAxis" xlink:label="loc_us-gaap_ConsolidationItemsAxis_7344FF46EAC4D29DC4A1CB40A175B2D0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_11AB74198E98BAEC94A3CB40A1751F82" xlink:to="loc_us-gaap_ConsolidationItemsAxis_7344FF46EAC4D29DC4A1CB40A175B2D0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_1225A25487A26E96B6E0CB40A1752CA3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConsolidationItemsAxis_7344FF46EAC4D29DC4A1CB40A175B2D0" xlink:to="loc_us-gaap_ConsolidationItemsDomain_1225A25487A26E96B6E0CB40A1752CA3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_1225A25487A26E96B6E0CB40A1752CA3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConsolidationItemsAxis_7344FF46EAC4D29DC4A1CB40A175B2D0" xlink:to="loc_us-gaap_ConsolidationItemsDomain_1225A25487A26E96B6E0CB40A1752CA3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_12BE3B935EB81E0A8679CB40A175E7BA" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_11AB74198E98BAEC94A3CB40A1751F82" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_12BE3B935EB81E0A8679CB40A175E7BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_0FFDA620DD2FE3D850E2CB40A1750B52_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_12BE3B935EB81E0A8679CB40A175E7BA" xlink:to="loc_us-gaap_SegmentDomain_0FFDA620DD2FE3D850E2CB40A1750B52_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_0FFDA620DD2FE3D850E2CB40A1750B52" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_12BE3B935EB81E0A8679CB40A175E7BA" xlink:to="loc_us-gaap_SegmentDomain_0FFDA620DD2FE3D850E2CB40A1750B52" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsegmentsAxis" xlink:label="loc_us-gaap_SubsegmentsAxis_177379CEB47F9E06A981CB40A175F139" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_11AB74198E98BAEC94A3CB40A1751F82" xlink:to="loc_us-gaap_SubsegmentsAxis_177379CEB47F9E06A981CB40A175F139" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsegmentsDomain" xlink:label="loc_us-gaap_SubsegmentsDomain_3C9AD69239C7126A49FECB40A175838B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_177379CEB47F9E06A981CB40A175F139" xlink:to="loc_us-gaap_SubsegmentsDomain_3C9AD69239C7126A49FECB40A175838B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsegmentsDomain" xlink:label="loc_us-gaap_SubsegmentsDomain_3C9AD69239C7126A49FECB40A175838B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_177379CEB47F9E06A981CB40A175F139" xlink:to="loc_us-gaap_SubsegmentsDomain_3C9AD69239C7126A49FECB40A175838B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsegmentsConsolidationItemsAxis" xlink:label="loc_us-gaap_SubsegmentsConsolidationItemsAxis_714719FF5629FA8082BFCB40A175F710" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_11AB74198E98BAEC94A3CB40A1751F82" xlink:to="loc_us-gaap_SubsegmentsConsolidationItemsAxis_714719FF5629FA8082BFCB40A175F710" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsegmentsConsolidationItemsDomain" xlink:label="loc_us-gaap_SubsegmentsConsolidationItemsDomain_DDFDC843E44F18461224CB40A175A753_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsConsolidationItemsAxis_714719FF5629FA8082BFCB40A175F710" xlink:to="loc_us-gaap_SubsegmentsConsolidationItemsDomain_DDFDC843E44F18461224CB40A175A753_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsegmentsConsolidationItemsDomain" xlink:label="loc_us-gaap_SubsegmentsConsolidationItemsDomain_DDFDC843E44F18461224CB40A175A753" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsConsolidationItemsAxis_714719FF5629FA8082BFCB40A175F710" xlink:to="loc_us-gaap_SubsegmentsConsolidationItemsDomain_DDFDC843E44F18461224CB40A175A753" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/StockBasedCompensation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/StockBasedCompensationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_51762783BCA8BDC8545AEF2331AF44D6" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E7CE31F7E6357E22BBCEEF2331AF2E4C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_51762783BCA8BDC8545AEF2331AF44D6" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E7CE31F7E6357E22BBCEEF2331AF2E4C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_E1F5466F75B7BEF92E3AEF2331AFDCBB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E7CE31F7E6357E22BBCEEF2331AF2E4C" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_E1F5466F75B7BEF92E3AEF2331AFDCBB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_41B4DC9872E964579720EF2331AF29E1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_E1F5466F75B7BEF92E3AEF2331AFDCBB" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_41B4DC9872E964579720EF2331AF29E1_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_41B4DC9872E964579720EF2331AF29E1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_E1F5466F75B7BEF92E3AEF2331AFDCBB" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_41B4DC9872E964579720EF2331AF29E1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_E08E9807E1DFD68B576CEF2331AF85A9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_41B4DC9872E964579720EF2331AF29E1" xlink:to="loc_us-gaap_MinimumMember_E08E9807E1DFD68B576CEF2331AF85A9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_331060AFDA65E1396429EF2331AFD3CE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_41B4DC9872E964579720EF2331AF29E1" xlink:to="loc_us-gaap_MaximumMember_331060AFDA65E1396429EF2331AFD3CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_E1D7EC1AE38D8D09A88FEF2331AFF069" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_51762783BCA8BDC8545AEF2331AF44D6" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_E1D7EC1AE38D8D09A88FEF2331AFF069" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_0566A300AE3844C1EDBEEF2331AFC928" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_51762783BCA8BDC8545AEF2331AF44D6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_0566A300AE3844C1EDBEEF2331AFC928" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_Weightedaveragefairvaluepriceofstockawardslower" xlink:label="loc_htld_Weightedaveragefairvaluepriceofstockawardslower_9F88D4BB945F354EF009EF2331AF1939" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_51762783BCA8BDC8545AEF2331AF44D6" xlink:to="loc_htld_Weightedaveragefairvaluepriceofstockawardslower_9F88D4BB945F354EF009EF2331AF1939" xlink:type="arc" />
    <link:loc xlink:href="htld-20170331.xsd#htld_Weightedaveragefairvaluepriceofstockawardsupper" xlink:label="loc_htld_Weightedaveragefairvaluepriceofstockawardsupper_F17824EC59BDFE9E59F4EF2331AFFD8E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_51762783BCA8BDC8545AEF2331AF44D6" xlink:to="loc_htld_Weightedaveragefairvaluepriceofstockawardsupper_F17824EC59BDFE9E59F4EF2331AFFD8E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_8882707FD92EC383FB77EF2331AF7C62" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_51762783BCA8BDC8545AEF2331AF44D6" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_8882707FD92EC383FB77EF2331AF7C62" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/StockBasedCompensationTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/SubsequentEvents" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.heartlandexpress.com/role/UseOfEstimates" xlink:type="extended" />
</link:linkbase>