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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019eb2c2-a330-760a-9278-82317fa79c4f,g:d2c327e2-d9e9-4c9e-926a-bda69060f203-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://schneider.com/role/CoverPage" xlink:type="simple" xlink:href="sndr-20260630.xsd#CoverPage"/>
  <link:definitionLink xlink:role="http://schneider.com/role/CoverPage" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_019eb2c2-a4c7-736d-8223-51fe1730289d" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_DocumentInformationTable_019eb2c2-a4c7-736d-8223-51fe1730289d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c7-7c25-ae72-ce3aba34b578" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_019eb2c2-a4c7-736d-8223-51fe1730289d" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c7-7c25-ae72-ce3aba34b578" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-7c25-ae72-ce3aba34b578_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c7-7c25-ae72-ce3aba34b578" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-7c25-ae72-ce3aba34b578_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-74fb-af22-04732d80fb91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c7-7c25-ae72-ce3aba34b578" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-74fb-af22-04732d80fb91" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019eb2c2-a4c7-7e19-a52e-00c2dc06e6ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-74fb-af22-04732d80fb91" xlink:to="loc_us-gaap_CommonClassAMember_019eb2c2-a4c7-7e19-a52e-00c2dc06e6ed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019eb2c2-a4c7-7d44-98b8-2b5a422ee8c2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-74fb-af22-04732d80fb91" xlink:to="loc_us-gaap_CommonClassBMember_019eb2c2-a4c7-7d44-98b8-2b5a422ee8c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019eb2c2-a4c7-74f5-838a-b584d92922ba" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_DocumentType_019eb2c2-a4c7-74f5-838a-b584d92922ba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_019eb2c2-a4c7-7c1c-a3f1-81c9f51377bd" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_DocumentQuarterlyReport_019eb2c2-a4c7-7c1c-a3f1-81c9f51377bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019eb2c2-a4c7-727a-b608-c27e979a0b20" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_DocumentPeriodEndDate_019eb2c2-a4c7-727a-b608-c27e979a0b20" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_019eb2c2-a4c7-7c3d-a233-f0d14f17900e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_DocumentTransitionReport_019eb2c2-a4c7-7c3d-a233-f0d14f17900e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019eb2c2-a4c7-7086-8ca3-0d20495a23ae" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityFileNumber_019eb2c2-a4c7-7086-8ca3-0d20495a23ae" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019eb2c2-a4c7-772e-aad3-1d95173d21c5" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityRegistrantName_019eb2c2-a4c7-772e-aad3-1d95173d21c5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019eb2c2-a4c7-7b0e-9a00-118a63de6209" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019eb2c2-a4c7-7b0e-9a00-118a63de6209" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019eb2c2-a4c7-72cf-9f1e-c66d7ef2f4ff" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityTaxIdentificationNumber_019eb2c2-a4c7-72cf-9f1e-c66d7ef2f4ff" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019eb2c2-a4c7-78bb-a9c3-9cbf181b37a5" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityAddressAddressLine1_019eb2c2-a4c7-78bb-a9c3-9cbf181b37a5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019eb2c2-a4c7-7981-b486-1610974266e8" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityAddressCityOrTown_019eb2c2-a4c7-7981-b486-1610974266e8" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019eb2c2-a4c7-788f-b429-92e70d67f4d8" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityAddressStateOrProvince_019eb2c2-a4c7-788f-b429-92e70d67f4d8" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019eb2c2-a4c7-7e01-87b2-1ac143e9f17b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityAddressPostalZipCode_019eb2c2-a4c7-7e01-87b2-1ac143e9f17b" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019eb2c2-a4c7-77a2-ab21-c681059f1f72" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_CityAreaCode_019eb2c2-a4c7-77a2-ab21-c681059f1f72" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019eb2c2-a4c7-72d3-b085-54abf8d7604c" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_LocalPhoneNumber_019eb2c2-a4c7-72d3-b085-54abf8d7604c" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019eb2c2-a4c7-7c6f-b9d5-2805282088e5" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_Security12bTitle_019eb2c2-a4c7-7c6f-b9d5-2805282088e5" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019eb2c2-a4c7-70f0-8286-1166a6239fb3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_TradingSymbol_019eb2c2-a4c7-70f0-8286-1166a6239fb3" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019eb2c2-a4c7-7ce2-b4ea-29a576e4e189" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_SecurityExchangeName_019eb2c2-a4c7-7ce2-b4ea-29a576e4e189" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_019eb2c2-a4c7-701e-aa03-6d8faf383b1f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityCurrentReportingStatus_019eb2c2-a4c7-701e-aa03-6d8faf383b1f" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_019eb2c2-a4c7-74a4-b4bf-7dddde5df240" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityInteractiveDataCurrent_019eb2c2-a4c7-74a4-b4bf-7dddde5df240" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_019eb2c2-a4c7-70e8-a24d-0e77c3b30d0a" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityFilerCategory_019eb2c2-a4c7-70e8-a24d-0e77c3b30d0a" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_019eb2c2-a4c7-7a70-9d41-5aa486b9564e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntitySmallBusiness_019eb2c2-a4c7-7a70-9d41-5aa486b9564e" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019eb2c2-a4c7-7811-8e73-c3cfaafaecbd" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityEmergingGrowthCompany_019eb2c2-a4c7-7811-8e73-c3cfaafaecbd" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_019eb2c2-a4c7-7884-9e0d-185c05623640" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityShellCompany_019eb2c2-a4c7-7884-9e0d-185c05623640" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_019eb2c2-a4c7-7d1e-b525-75ded1923a67" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_019eb2c2-a4c7-7d1e-b525-75ded1923a67" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019eb2c2-a4c7-715a-affe-3eb69324d7b6" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_AmendmentFlag_019eb2c2-a4c7-715a-affe-3eb69324d7b6" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_019eb2c2-a4c7-759b-affd-b494c26dbe44" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_DocumentFiscalYearFocus_019eb2c2-a4c7-759b-affd-b494c26dbe44" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_019eb2c2-a4c7-7748-8270-5ebf7b748a63" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_DocumentFiscalPeriodFocus_019eb2c2-a4c7-7748-8270-5ebf7b748a63" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019eb2c2-a4c7-7b03-aadd-3640f517e922" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_EntityCentralIndexKey_019eb2c2-a4c7-7b03-aadd-3640f517e922" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_019eb2c2-a4c7-7013-9a17-dc3c3d96149f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019eb2c2-a4c7-7258-b41b-4b5f42b54130" xlink:to="loc_dei_CurrentFiscalYearEndDate_019eb2c2-a4c7-7013-9a17-dc3c3d96149f" xlink:type="arc" order="28"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/ConsolidatedBalanceSheetsUnaudited" xlink:type="simple" xlink:href="sndr-20260630.xsd#ConsolidatedBalanceSheetsUnaudited"/>
  <link:definitionLink xlink:role="http://schneider.com/role/ConsolidatedBalanceSheetsUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019eb2c2-a4c7-74bc-a1f1-47d7ceeaa534" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019eb2c2-a4c7-729d-b52f-b149bc89ea56" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c7-74bc-a1f1-47d7ceeaa534" xlink:to="loc_us-gaap_StatementTable_019eb2c2-a4c7-729d-b52f-b149bc89ea56" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c7-742d-a33f-d2f95c5299c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019eb2c2-a4c7-729d-b52f-b149bc89ea56" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c7-742d-a33f-d2f95c5299c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-742d-a33f-d2f95c5299c4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c7-742d-a33f-d2f95c5299c4" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-742d-a33f-d2f95c5299c4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-745a-a3c2-b9f259a81928" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c7-742d-a33f-d2f95c5299c4" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-745a-a3c2-b9f259a81928" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_019eb2c2-a4c7-774b-8286-e8f4b1543bee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-745a-a3c2-b9f259a81928" xlink:to="loc_us-gaap_PreferredStockMember_019eb2c2-a4c7-774b-8286-e8f4b1543bee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019eb2c2-a4c7-7956-a082-ca52a2596d55" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-745a-a3c2-b9f259a81928" xlink:to="loc_us-gaap_CommonClassAMember_019eb2c2-a4c7-7956-a082-ca52a2596d55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019eb2c2-a4c7-7c13-a0aa-e8ce41e00d1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c7-745a-a3c2-b9f259a81928" xlink:to="loc_us-gaap_CommonClassBMember_019eb2c2-a4c7-7c13-a0aa-e8ce41e00d1e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_019eb2c2-a4c7-7acd-ab11-bef13e799deb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c7-74bc-a1f1-47d7ceeaa534" xlink:to="loc_us-gaap_AssetsAbstract_019eb2c2-a4c7-7acd-ab11-bef13e799deb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract_019eb2c2-a4c7-7229-88b9-8eeeb504116e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019eb2c2-a4c7-7acd-ab11-bef13e799deb" xlink:to="loc_us-gaap_AssetsCurrentAbstract_019eb2c2-a4c7-7229-88b9-8eeeb504116e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019eb2c2-a4c7-7758-b545-d36e997d862c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019eb2c2-a4c7-7229-88b9-8eeeb504116e" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019eb2c2-a4c7-7758-b545-d36e997d862c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_019eb2c2-a4c7-738a-96f9-29244fb24d1b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecuritiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019eb2c2-a4c7-7229-88b9-8eeeb504116e" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_019eb2c2-a4c7-738a-96f9-29244fb24d1b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019eb2c2-a4c7-7283-afad-f2819c07aea0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019eb2c2-a4c7-7229-88b9-8eeeb504116e" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019eb2c2-a4c7-7283-afad-f2819c07aea0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherReceivablesNetCurrent_019eb2c2-a4c7-70e7-b6ca-6c0e47d188a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherReceivablesNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019eb2c2-a4c7-7229-88b9-8eeeb504116e" xlink:to="loc_us-gaap_OtherReceivablesNetCurrent_019eb2c2-a4c7-70e7-b6ca-6c0e47d188a8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesTypeLeaseNetInvestmentInLeaseAfterAllowanceForCreditLossCurrent_019eb2c2-a4c7-7570-903f-d5303d77db51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SalesTypeLeaseNetInvestmentInLeaseAfterAllowanceForCreditLossCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019eb2c2-a4c7-7229-88b9-8eeeb504116e" xlink:to="loc_us-gaap_SalesTypeLeaseNetInvestmentInLeaseAfterAllowanceForCreditLossCurrent_019eb2c2-a4c7-7570-903f-d5303d77db51" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_019eb2c2-a4c7-79b8-ba66-cb2302ada6fe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019eb2c2-a4c7-7229-88b9-8eeeb504116e" xlink:to="loc_us-gaap_InventoryNet_019eb2c2-a4c7-79b8-ba66-cb2302ada6fe" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019eb2c2-a4c7-7a04-8a48-bfad46a432f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019eb2c2-a4c7-7229-88b9-8eeeb504116e" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019eb2c2-a4c7-7a04-8a48-bfad46a432f9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019eb2c2-a4c7-72b2-9c20-5b198381c18f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019eb2c2-a4c7-7229-88b9-8eeeb504116e" xlink:to="loc_us-gaap_AssetsCurrent_019eb2c2-a4c7-72b2-9c20-5b198381c18f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsNoncurrentAbstract_019eb2c2-a4c7-702e-a7c7-fdbf37662e46" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsNoncurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019eb2c2-a4c7-7acd-ab11-bef13e799deb" xlink:to="loc_us-gaap_AssetsNoncurrentAbstract_019eb2c2-a4c7-702e-a7c7-fdbf37662e46" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract_019eb2c2-a4c7-7830-82de-99f78efbb62f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsNoncurrentAbstract_019eb2c2-a4c7-702e-a7c7-fdbf37662e46" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract_019eb2c2-a4c7-7830-82de-99f78efbb62f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentGross_019eb2c2-a4c7-7e06-b373-ad7e0e53af6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MachineryAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract_019eb2c2-a4c7-7830-82de-99f78efbb62f" xlink:to="loc_us-gaap_MachineryAndEquipmentGross_019eb2c2-a4c7-7e06-b373-ad7e0e53af6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_LandBuildingsAndImprovements_019eb2c2-a4c7-7f73-af3a-153d9abf8565" xlink:href="sndr-20260630.xsd#sndr_LandBuildingsAndImprovements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract_019eb2c2-a4c7-7830-82de-99f78efbb62f" xlink:to="loc_sndr_LandBuildingsAndImprovements_019eb2c2-a4c7-7f73-af3a-153d9abf8565" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentOther_019eb2c2-a4c7-7ee2-9711-48ad7c5b2da8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract_019eb2c2-a4c7-7830-82de-99f78efbb62f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentOther_019eb2c2-a4c7-7ee2-9711-48ad7c5b2da8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019eb2c2-a4c7-7a5d-9e7a-83465bfd4d8c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract_019eb2c2-a4c7-7830-82de-99f78efbb62f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019eb2c2-a4c7-7a5d-9e7a-83465bfd4d8c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019eb2c2-a4c7-7cee-896a-681a7f8db5b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract_019eb2c2-a4c7-7830-82de-99f78efbb62f" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019eb2c2-a4c7-7cee-896a-681a7f8db5b1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019eb2c2-a4c7-77bb-adbe-c6ccc4dc4b75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract_019eb2c2-a4c7-7830-82de-99f78efbb62f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019eb2c2-a4c7-77bb-adbe-c6ccc4dc4b75" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesTypeLeaseNetInvestmentInLeaseAfterAllowanceForCreditLossNoncurrent_019eb2c2-a4c7-716f-a800-34171ab80652" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SalesTypeLeaseNetInvestmentInLeaseAfterAllowanceForCreditLossNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract_019eb2c2-a4c7-7830-82de-99f78efbb62f" xlink:to="loc_us-gaap_SalesTypeLeaseNetInvestmentInLeaseAfterAllowanceForCreditLossNoncurrent_019eb2c2-a4c7-716f-a800-34171ab80652" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019eb2c2-a4c7-7314-8d0e-bcece3b8811b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsNoncurrentAbstract_019eb2c2-a4c7-702e-a7c7-fdbf37662e46" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019eb2c2-a4c7-7314-8d0e-bcece3b8811b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019eb2c2-a4c7-709d-9b96-f7942e733063" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsNoncurrentAbstract_019eb2c2-a4c7-702e-a7c7-fdbf37662e46" xlink:to="loc_us-gaap_Goodwill_019eb2c2-a4c7-709d-9b96-f7942e733063" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsNoncurrent_019eb2c2-a4c7-7847-8e73-19a49e084c27" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsNoncurrentAbstract_019eb2c2-a4c7-702e-a7c7-fdbf37662e46" xlink:to="loc_us-gaap_AssetsNoncurrent_019eb2c2-a4c7-7847-8e73-19a49e084c27" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019eb2c2-a4c7-7922-97b2-748f4441d815" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019eb2c2-a4c7-7acd-ab11-bef13e799deb" xlink:to="loc_us-gaap_Assets_019eb2c2-a4c7-7922-97b2-748f4441d815" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019eb2c2-a4c8-742b-bdb5-ce81894ca92e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c7-74bc-a1f1-47d7ceeaa534" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019eb2c2-a4c8-742b-bdb5-ce81894ca92e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_019eb2c2-a4c8-7f8c-aac4-b3498378c711" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019eb2c2-a4c8-742b-bdb5-ce81894ca92e" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_019eb2c2-a4c8-7f8c-aac4-b3498378c711" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableTradeCurrent_019eb2c2-a4c8-7772-b537-6ee6faa5ba94" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableTradeCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019eb2c2-a4c8-7f8c-aac4-b3498378c711" xlink:to="loc_us-gaap_AccountsPayableTradeCurrent_019eb2c2-a4c8-7772-b537-6ee6faa5ba94" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019eb2c2-a4c8-7c6c-9808-82a353340fff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019eb2c2-a4c8-7f8c-aac4-b3498378c711" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_019eb2c2-a4c8-7c6c-9808-82a353340fff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedInsuranceCurrent_019eb2c2-a4c8-72e8-98ca-624b81bf40b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedInsuranceCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019eb2c2-a4c8-7f8c-aac4-b3498378c711" xlink:to="loc_us-gaap_AccruedInsuranceCurrent_019eb2c2-a4c8-72e8-98ca-624b81bf40b9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_019eb2c2-a4c8-737e-885a-8451f02805b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019eb2c2-a4c8-7f8c-aac4-b3498378c711" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_019eb2c2-a4c8-737e-885a-8451f02805b6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesCurrent_019eb2c2-a4c8-79bb-8108-3ba121346973" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019eb2c2-a4c8-7f8c-aac4-b3498378c711" xlink:to="loc_us-gaap_OtherAccruedLiabilitiesCurrent_019eb2c2-a4c8-79bb-8108-3ba121346973" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019eb2c2-a4c8-72b7-8182-d4e5f70ce147" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019eb2c2-a4c8-7f8c-aac4-b3498378c711" xlink:to="loc_us-gaap_LiabilitiesCurrent_019eb2c2-a4c8-72b7-8182-d4e5f70ce147" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrentAbstract_019eb2c2-a4c8-7dfa-a4c1-4ea283976899" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesNoncurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019eb2c2-a4c8-742b-bdb5-ce81894ca92e" xlink:to="loc_us-gaap_LiabilitiesNoncurrentAbstract_019eb2c2-a4c8-7dfa-a4c1-4ea283976899" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019eb2c2-a4c8-7c19-9849-aeae6c005d8f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019eb2c2-a4c8-7dfa-a4c1-4ea283976899" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019eb2c2-a4c8-7c19-9849-aeae6c005d8f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedInsuranceNoncurrent_019eb2c2-a4c8-705b-9905-b18f33ac5401" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedInsuranceNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019eb2c2-a4c8-7dfa-a4c1-4ea283976899" xlink:to="loc_us-gaap_AccruedInsuranceNoncurrent_019eb2c2-a4c8-705b-9905-b18f33ac5401" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019eb2c2-a4c8-787a-a756-d70801137bf8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019eb2c2-a4c8-7dfa-a4c1-4ea283976899" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019eb2c2-a4c8-787a-a756-d70801137bf8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_019eb2c2-a4c8-7b99-a741-59ebeb92cec2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019eb2c2-a4c8-7dfa-a4c1-4ea283976899" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_019eb2c2-a4c8-7b99-a741-59ebeb92cec2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrent_019eb2c2-a4c8-7ede-a258-7fb767e1350a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019eb2c2-a4c8-7dfa-a4c1-4ea283976899" xlink:to="loc_us-gaap_LiabilitiesNoncurrent_019eb2c2-a4c8-7ede-a258-7fb767e1350a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019eb2c2-a4c8-7eea-aaa1-d9e178bb0761" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019eb2c2-a4c8-742b-bdb5-ce81894ca92e" xlink:to="loc_us-gaap_Liabilities_019eb2c2-a4c8-7eea-aaa1-d9e178bb0761" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract_019eb2c2-a4c8-7d93-8c00-b2a1638808af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019eb2c2-a4c8-742b-bdb5-ce81894ca92e" xlink:to="loc_us-gaap_StockholdersEquityAbstract_019eb2c2-a4c8-7d93-8c00-b2a1638808af" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_019eb2c2-a4c8-79d5-bcda-fb3f94300af5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019eb2c2-a4c8-7d93-8c00-b2a1638808af" xlink:to="loc_us-gaap_PreferredStockValue_019eb2c2-a4c8-79d5-bcda-fb3f94300af5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019eb2c2-a4c8-795e-91b4-c9f524846988" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019eb2c2-a4c8-7d93-8c00-b2a1638808af" xlink:to="loc_us-gaap_CommonStockValue_019eb2c2-a4c8-795e-91b4-c9f524846988" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_019eb2c2-a4c8-748c-91f6-39880d515183" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019eb2c2-a4c8-7d93-8c00-b2a1638808af" xlink:to="loc_us-gaap_AdditionalPaidInCapital_019eb2c2-a4c8-748c-91f6-39880d515183" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019eb2c2-a4c8-793d-8171-a11de0ba72d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019eb2c2-a4c8-7d93-8c00-b2a1638808af" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019eb2c2-a4c8-793d-8171-a11de0ba72d5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019eb2c2-a4c8-7d93-afba-dbbe1701fadf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019eb2c2-a4c8-7d93-8c00-b2a1638808af" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019eb2c2-a4c8-7d93-afba-dbbe1701fadf" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValue_019eb2c2-a4c8-71ed-bbcc-897dd0fa2c66" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019eb2c2-a4c8-7d93-8c00-b2a1638808af" xlink:to="loc_us-gaap_TreasuryStockValue_019eb2c2-a4c8-71ed-bbcc-897dd0fa2c66" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019eb2c2-a4c8-7293-a690-dbf321d408e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019eb2c2-a4c8-7d93-8c00-b2a1638808af" xlink:to="loc_us-gaap_StockholdersEquity_019eb2c2-a4c8-7293-a690-dbf321d408e6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019eb2c2-a4c8-7c47-a2a9-c61e0952225e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019eb2c2-a4c8-742b-bdb5-ce81894ca92e" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_019eb2c2-a4c8-7c47-a2a9-c61e0952225e" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/ConsolidatedStatementsShareholdersEquity" xlink:type="simple" xlink:href="sndr-20260630.xsd#ConsolidatedStatementsShareholdersEquity"/>
  <link:definitionLink xlink:role="http://schneider.com/role/ConsolidatedStatementsShareholdersEquity" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-7eee-b8af-771102fe7890" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019eb2c2-a4c8-7883-9f9d-59e1bbefc452" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-7eee-b8af-771102fe7890" xlink:to="loc_us-gaap_StatementTable_019eb2c2-a4c8-7883-9f9d-59e1bbefc452" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019eb2c2-a4c8-75bc-83c2-d7c38e081bd3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019eb2c2-a4c8-7883-9f9d-59e1bbefc452" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019eb2c2-a4c8-75bc-83c2-d7c38e081bd3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019eb2c2-a4c8-75bc-83c2-d7c38e081bd3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019eb2c2-a4c8-75bc-83c2-d7c38e081bd3" xlink:to="loc_us-gaap_EquityComponentDomain_019eb2c2-a4c8-75bc-83c2-d7c38e081bd3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019eb2c2-a4c8-7f04-b520-aa80bbe1be01" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019eb2c2-a4c8-75bc-83c2-d7c38e081bd3" xlink:to="loc_us-gaap_EquityComponentDomain_019eb2c2-a4c8-7f04-b520-aa80bbe1be01" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019eb2c2-a4c8-7732-ba79-4e6fa35eae52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019eb2c2-a4c8-7f04-b520-aa80bbe1be01" xlink:to="loc_us-gaap_CommonStockMember_019eb2c2-a4c8-7732-ba79-4e6fa35eae52" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019eb2c2-a4c8-76b0-b41d-aa7303a629f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019eb2c2-a4c8-7f04-b520-aa80bbe1be01" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019eb2c2-a4c8-76b0-b41d-aa7303a629f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019eb2c2-a4c8-7db7-8673-b971ec386723" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019eb2c2-a4c8-7f04-b520-aa80bbe1be01" xlink:to="loc_us-gaap_RetainedEarningsMember_019eb2c2-a4c8-7db7-8673-b971ec386723" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019eb2c2-a4c8-7c2f-8a1e-a3dfedb3f691" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019eb2c2-a4c8-7f04-b520-aa80bbe1be01" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019eb2c2-a4c8-7c2f-8a1e-a3dfedb3f691" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_019eb2c2-a4c8-74f9-b628-4410594d268f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019eb2c2-a4c8-7f04-b520-aa80bbe1be01" xlink:to="loc_us-gaap_TreasuryStockCommonMember_019eb2c2-a4c8-74f9-b628-4410594d268f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-75bb-8c8d-6d418efe6401" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019eb2c2-a4c8-7883-9f9d-59e1bbefc452" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-75bb-8c8d-6d418efe6401" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-75bb-8c8d-6d418efe6401_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-75bb-8c8d-6d418efe6401" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-75bb-8c8d-6d418efe6401_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7d3a-a3d1-bf4955ae41df" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-75bb-8c8d-6d418efe6401" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7d3a-a3d1-bf4955ae41df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019eb2c2-a4c8-7d62-a229-af4ac2fb3065" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7d3a-a3d1-bf4955ae41df" xlink:to="loc_us-gaap_CommonClassAMember_019eb2c2-a4c8-7d62-a229-af4ac2fb3065" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019eb2c2-a4c8-72e7-8d55-68378ffc3f8d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7d3a-a3d1-bf4955ae41df" xlink:to="loc_us-gaap_CommonClassBMember_019eb2c2-a4c8-72e7-8d55-68378ffc3f8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-7eee-b8af-771102fe7890" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019eb2c2-a4c8-70ba-835f-f71faad61b19" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:to="loc_us-gaap_StockholdersEquity_019eb2c2-a4c8-70ba-835f-f71faad61b19" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019eb2c2-a4c8-716c-8614-cb19d57d9040" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:to="loc_us-gaap_NetIncomeLoss_019eb2c2-a4c8-716c-8614-cb19d57d9040" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019eb2c2-a4c8-7104-9d81-c04d94ed793d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019eb2c2-a4c8-7104-9d81-c04d94ed793d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019eb2c2-a4c8-7ffe-b784-c78615ea6cad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019eb2c2-a4c8-7ffe-b784-c78615ea6cad" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019eb2c2-a4c8-7cc6-966b-45e7523ad3ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019eb2c2-a4c8-7cc6-966b-45e7523ad3ea" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCash_019eb2c2-a4c8-7f1f-9602-a6a8585fd96f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:to="loc_us-gaap_DividendsCash_019eb2c2-a4c8-7f1f-9602-a6a8585fd96f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_019eb2c2-a4c8-7dca-96e7-3a572105e58e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_019eb2c2-a4c8-7dca-96e7-3a572105e58e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_019fa154-47e8-710e-aeaa-9b8ff6d95db1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_019fa154-47e8-710e-aeaa-9b8ff6d95db1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_019fa154-5eab-7782-a23f-bd0a0286a3e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_019fa154-5eab-7782-a23f-bd0a0286a3e4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_019eb2c2-a4c8-79ec-b44d-b9b7d275f88b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019eb2c2-a4c8-7e44-80a9-c1154d9fdf4f" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_019eb2c2-a4c8-79ec-b44d-b9b7d275f88b" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019faa72-bb1b-7c24-8d74-dc2d3979c013" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/ConsolidatedBalanceSheetsUnauditedParenthetical" xlink:type="simple" xlink:href="sndr-20260630.xsd#ConsolidatedBalanceSheetsUnauditedParenthetical"/>
  <link:definitionLink xlink:role="http://schneider.com/role/ConsolidatedBalanceSheetsUnauditedParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019eb2c2-a4c8-7a81-b960-4f38272672c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_us-gaap_StatementTable_019eb2c2-a4c8-7a81-b960-4f38272672c9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementAxis_019eb2c2-a4c8-7d32-970c-09ab499ccae2" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019eb2c2-a4c8-7a81-b960-4f38272672c9" xlink:to="loc_srt_RestatementAxis_019eb2c2-a4c8-7d32-970c-09ab499ccae2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_019eb2c2-a4c8-7d32-970c-09ab499ccae2_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RestatementAxis_019eb2c2-a4c8-7d32-970c-09ab499ccae2" xlink:to="loc_srt_RestatementDomain_019eb2c2-a4c8-7d32-970c-09ab499ccae2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_019eb2c2-a4c8-763c-a519-c989efa324c8" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RestatementAxis_019eb2c2-a4c8-7d32-970c-09ab499ccae2" xlink:to="loc_srt_RestatementDomain_019eb2c2-a4c8-763c-a519-c989efa324c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-7ca4-8bf1-0522fc9a16fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019eb2c2-a4c8-7a81-b960-4f38272672c9" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-7ca4-8bf1-0522fc9a16fa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7ca4-8bf1-0522fc9a16fa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-7ca4-8bf1-0522fc9a16fa" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7ca4-8bf1-0522fc9a16fa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7267-bcc6-f30d377db576" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-7ca4-8bf1-0522fc9a16fa" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7267-bcc6-f30d377db576" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_019eb2c2-a4c8-7756-9b4c-846323f4c9d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7267-bcc6-f30d377db576" xlink:to="loc_us-gaap_PreferredStockMember_019eb2c2-a4c8-7756-9b4c-846323f4c9d5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019eb2c2-a4c8-775a-ac83-12dbb9f67275" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7267-bcc6-f30d377db576" xlink:to="loc_us-gaap_CommonClassAMember_019eb2c2-a4c8-775a-ac83-12dbb9f67275" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019eb2c2-a4c8-7845-9d61-7fc51ccee6b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7267-bcc6-f30d377db576" xlink:to="loc_us-gaap_CommonClassBMember_019eb2c2-a4c8-7845-9d61-7fc51ccee6b3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_019eb2c2-a4c8-7358-89ca-168206d841ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7267-bcc6-f30d377db576" xlink:to="loc_us-gaap_TreasuryStockCommonMember_019eb2c2-a4c8-7358-89ca-168206d841ea" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_AccountsReceivableAllowanceForCreditLossAndRevenueAdjustmentsCurrent_019eb2c2-a4c8-76bf-ae8b-9879bc85ea45" xlink:href="sndr-20260630.xsd#sndr_AccountsReceivableAllowanceForCreditLossAndRevenueAdjustmentsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_sndr_AccountsReceivableAllowanceForCreditLossAndRevenueAdjustmentsCurrent_019eb2c2-a4c8-76bf-ae8b-9879bc85ea45" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesTypeLeaseNetInvestmentInLeaseAllowanceForCreditLoss_019eb2c2-a4c8-785f-9df0-5548dad50d3a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SalesTypeLeaseNetInvestmentInLeaseAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_us-gaap_SalesTypeLeaseNetInvestmentInLeaseAllowanceForCreditLoss_019eb2c2-a4c8-785f-9df0-5548dad50d3a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesTypeLeaseNetInvestmentInLeaseAllowanceForCreditLoss_019eb2c2-a4c8-70ab-8360-324e7c6ebd2b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SalesTypeLeaseNetInvestmentInLeaseAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesTypeLeaseNetInvestmentInLeaseAllowanceForCreditLoss_019eb2c2-a4c8-7e0e-aae9-fbc21d14fdbf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SalesTypeLeaseNetInvestmentInLeaseAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019eb2c2-a4c8-7217-a3f3-1461bd7be930" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019eb2c2-a4c8-7217-a3f3-1461bd7be930" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_019eb2c2-a4c8-75f8-9481-e70aac64b22b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_019eb2c2-a4c8-75f8-9481-e70aac64b22b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_019eb2c2-a4c8-7cc2-85d8-2723743b7f15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_019eb2c2-a4c8-7cc2-85d8-2723743b7f15" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_019eb2c2-a4c8-7a20-bbb3-f5379b43752c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_us-gaap_PreferredStockSharesIssued_019eb2c2-a4c8-7a20-bbb3-f5379b43752c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_019eb2c2-a4c8-709e-983f-37c14d1882bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_019eb2c2-a4c8-709e-983f-37c14d1882bd" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_019eb2c2-a4c8-755f-9aec-a4931d4a6edc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_019eb2c2-a4c8-755f-9aec-a4931d4a6edc" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019eb2c2-a4c8-7a64-98bd-a6ce2ed546c3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019eb2c2-a4c8-7a64-98bd-a6ce2ed546c3" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019eb2c2-a4c8-77d5-adba-28e57c71358f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_us-gaap_CommonStockSharesIssued_019eb2c2-a4c8-77d5-adba-28e57c71358f" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019eb2c2-a4c8-719c-ac88-ce33f3f69209" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019eb2c2-a4c8-70cc-9ea3-a7367a7a288f" xlink:to="loc_us-gaap_TreasuryStockCommonShares_019eb2c2-a4c8-719c-ac88-ce33f3f69209" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/BusinessCombinationsandAssetAcquisitionsAcquisitionDetailsDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#BusinessCombinationsandAssetAcquisitionsAcquisitionDetailsDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/BusinessCombinationsandAssetAcquisitionsAcquisitionDetailsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019eb2c2-a4c8-7ba9-9120-c1975c29c588" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019eb2c2-a4c8-7e2d-8350-b7d1c7aadc46" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019eb2c2-a4c8-7ba9-9120-c1975c29c588" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019eb2c2-a4c8-7e2d-8350-b7d1c7aadc46" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-740d-8668-3a433f6bf0e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019eb2c2-a4c8-7e2d-8350-b7d1c7aadc46" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-740d-8668-3a433f6bf0e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-740d-8668-3a433f6bf0e2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-740d-8668-3a433f6bf0e2" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-740d-8668-3a433f6bf0e2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7992-baac-5998980161e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-740d-8668-3a433f6bf0e2" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7992-baac-5998980161e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementAxis_019eb2c2-a4c8-7451-8397-57be204cac38" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019eb2c2-a4c8-7e2d-8350-b7d1c7aadc46" xlink:to="loc_srt_RestatementAxis_019eb2c2-a4c8-7451-8397-57be204cac38" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_019eb2c2-a4c8-7451-8397-57be204cac38_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RestatementAxis_019eb2c2-a4c8-7451-8397-57be204cac38" xlink:to="loc_srt_RestatementDomain_019eb2c2-a4c8-7451-8397-57be204cac38_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_019eb2c2-a4c8-724d-a770-58c63c22e1bd" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RestatementAxis_019eb2c2-a4c8-7451-8397-57be204cac38" xlink:to="loc_srt_RestatementDomain_019eb2c2-a4c8-724d-a770-58c63c22e1bd" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/RevenueRecognitionDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#RevenueRecognitionDisaggregationofRevenueDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/RevenueRecognitionDisaggregationofRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019eb2c2-a4c8-72fd-ad68-e9d7f33a13af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019eb2c2-a4c8-74cf-96bb-709478dd652a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019eb2c2-a4c8-72fd-ad68-e9d7f33a13af" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019eb2c2-a4c8-74cf-96bb-709478dd652a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019eb2c2-a4c8-7d78-93f3-1c345c8df0c8" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019eb2c2-a4c8-74cf-96bb-709478dd652a" xlink:to="loc_srt_ProductOrServiceAxis_019eb2c2-a4c8-7d78-93f3-1c345c8df0c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-7d78-93f3-1c345c8df0c8_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019eb2c2-a4c8-7d78-93f3-1c345c8df0c8" xlink:to="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-7d78-93f3-1c345c8df0c8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-78da-889d-e69272680bf3" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019eb2c2-a4c8-7d78-93f3-1c345c8df0c8" xlink:to="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-78da-889d-e69272680bf3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_TransportationMember_019eb2c2-a4c8-77b7-8e83-49b0b371e4c5" xlink:href="sndr-20260630.xsd#sndr_TransportationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-78da-889d-e69272680bf3" xlink:to="loc_sndr_TransportationMember_019eb2c2-a4c8-77b7-8e83-49b0b371e4c5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_LogisticsManagementMember_019eb2c2-a4c8-70eb-b393-cac990c8dd9f" xlink:href="sndr-20260630.xsd#sndr_LogisticsManagementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-78da-889d-e69272680bf3" xlink:to="loc_sndr_LogisticsManagementMember_019eb2c2-a4c8-70eb-b393-cac990c8dd9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_OtherMember_019eb2c2-a4c8-7ffb-b2f4-82204c3ccafd" xlink:href="sndr-20260630.xsd#sndr_OtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-78da-889d-e69272680bf3" xlink:to="loc_sndr_OtherMember_019eb2c2-a4c8-7ffb-b2f4-82204c3ccafd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019eb2c2-a4c8-7175-b9db-ad3c69dcad39" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019eb2c2-a4c8-72fd-ad68-e9d7f33a13af" xlink:to="loc_us-gaap_Revenues_019eb2c2-a4c8-7175-b9db-ad3c69dcad39" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/RevenueRecognitionRevenueRemainingPerformanceObligationDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#RevenueRecognitionRevenueRemainingPerformanceObligationDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/RevenueRecognitionRevenueRemainingPerformanceObligationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019eb2c2-a4c8-707d-88d6-530d0f7edce3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019eb2c2-a4c8-79b6-9f89-7fd30b8018a5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019eb2c2-a4c8-707d-88d6-530d0f7edce3" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019eb2c2-a4c8-79b6-9f89-7fd30b8018a5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_019eb2c2-a4c8-7c4a-a20d-d7b2575beaa9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimingOfTransferOfGoodOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019eb2c2-a4c8-79b6-9f89-7fd30b8018a5" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_019eb2c2-a4c8-7c4a-a20d-d7b2575beaa9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019eb2c2-a4c8-7c4a-a20d-d7b2575beaa9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_019eb2c2-a4c8-7c4a-a20d-d7b2575beaa9" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019eb2c2-a4c8-7c4a-a20d-d7b2575beaa9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019eb2c2-a4c8-7f79-8da0-8a742f86c005" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_019eb2c2-a4c8-7c4a-a20d-d7b2575beaa9" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019eb2c2-a4c8-7f79-8da0-8a742f86c005" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_ExpectedtoberecognizedwithinoneyearMember_019eb2c2-a4c8-7b0c-ace0-0520471c1471" xlink:href="sndr-20260630.xsd#sndr_ExpectedtoberecognizedwithinoneyearMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019eb2c2-a4c8-7f79-8da0-8a742f86c005" xlink:to="loc_sndr_ExpectedtoberecognizedwithinoneyearMember_019eb2c2-a4c8-7b0c-ace0-0520471c1471" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_ExpectedtoberecognizedafteroneyearMember_019eb2c2-a4c8-72ca-b17f-b2c46cfa3cf6" xlink:href="sndr-20260630.xsd#sndr_ExpectedtoberecognizedafteroneyearMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019eb2c2-a4c8-7f79-8da0-8a742f86c005" xlink:to="loc_sndr_ExpectedtoberecognizedafteroneyearMember_019eb2c2-a4c8-72ca-b17f-b2c46cfa3cf6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019eb2c2-a4c8-7c8e-b886-83a728122294" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019eb2c2-a4c8-79b6-9f89-7fd30b8018a5" xlink:to="loc_srt_ProductOrServiceAxis_019eb2c2-a4c8-7c8e-b886-83a728122294" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-7c8e-b886-83a728122294_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019eb2c2-a4c8-7c8e-b886-83a728122294" xlink:to="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-7c8e-b886-83a728122294_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-7aec-b445-7e14252ebfbd" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019eb2c2-a4c8-7c8e-b886-83a728122294" xlink:to="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-7aec-b445-7e14252ebfbd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_TransportationMember_019eb2c2-a4c8-77bf-b4a6-fbab559f389d" xlink:href="sndr-20260630.xsd#sndr_TransportationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-7aec-b445-7e14252ebfbd" xlink:to="loc_sndr_TransportationMember_019eb2c2-a4c8-77bf-b4a6-fbab559f389d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_LogisticsManagementMember_019eb2c2-a4c8-77b2-b573-6559108c6b7d" xlink:href="sndr-20260630.xsd#sndr_LogisticsManagementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019eb2c2-a4c8-7aec-b445-7e14252ebfbd" xlink:to="loc_sndr_LogisticsManagementMember_019eb2c2-a4c8-77b2-b573-6559108c6b7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019eb2c2-a4c8-718e-b39c-edcd76b40544" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019eb2c2-a4c8-707d-88d6-530d0f7edce3" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019eb2c2-a4c8-718e-b39c-edcd76b40544" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/FairValueRecurringFairValueMeasurementsDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#FairValueRecurringFairValueMeasurementsDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/FairValueRecurringFairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019eb2c2-a4c8-7e98-a6df-6f7fe0f68e64" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019eb2c2-a4c8-7a1d-8940-e374c546a28a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019eb2c2-a4c8-7e98-a6df-6f7fe0f68e64" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019eb2c2-a4c8-7a1d-8940-e374c546a28a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019eb2c2-a4c8-7724-a773-53e3b4f00b2b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019eb2c2-a4c8-7a1d-8940-e374c546a28a" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019eb2c2-a4c8-7724-a773-53e3b4f00b2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019eb2c2-a4c8-7724-a773-53e3b4f00b2b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019eb2c2-a4c8-7724-a773-53e3b4f00b2b" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019eb2c2-a4c8-7724-a773-53e3b4f00b2b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019eb2c2-a4c8-74ad-91f5-a4d3fb2bfa20" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019eb2c2-a4c8-7724-a773-53e3b4f00b2b" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019eb2c2-a4c8-74ad-91f5-a4d3fb2bfa20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_019eb2c2-a4c8-79fc-8531-254b54551cfa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_019eb2c2-a4c8-74ad-91f5-a4d3fb2bfa20" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_019eb2c2-a4c8-79fc-8531-254b54551cfa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019eb2c2-a4c8-74bc-9535-4f2e4921b3d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019eb2c2-a4c8-7a1d-8940-e374c546a28a" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019eb2c2-a4c8-74bc-9535-4f2e4921b3d0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019eb2c2-a4c8-74bc-9535-4f2e4921b3d0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019eb2c2-a4c8-74bc-9535-4f2e4921b3d0" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019eb2c2-a4c8-74bc-9535-4f2e4921b3d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019eb2c2-a4c8-7420-9e54-aecdafac2195" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019eb2c2-a4c8-74bc-9535-4f2e4921b3d0" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019eb2c2-a4c8-7420-9e54-aecdafac2195" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019eb2c2-a4c8-7c12-9675-9b0486fd282c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019eb2c2-a4c8-7420-9e54-aecdafac2195" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019eb2c2-a4c8-7c12-9675-9b0486fd282c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019eb2c2-a4c8-796a-b3a7-d10199823fd5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019eb2c2-a4c8-7420-9e54-aecdafac2195" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019eb2c2-a4c8-796a-b3a7-d10199823fd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFVNINoncurrent_019eb2c2-a4c8-7363-8ade-adee6b472f46" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesFVNINoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019eb2c2-a4c8-7e98-a6df-6f7fe0f68e64" xlink:to="loc_us-gaap_EquitySecuritiesFVNINoncurrent_019eb2c2-a4c8-7363-8ade-adee6b472f46" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsFairValueDisclosure_019eb2c2-a4c8-79ae-a8d0-02babd8a01c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019eb2c2-a4c8-7e98-a6df-6f7fe0f68e64" xlink:to="loc_us-gaap_InvestmentsFairValueDisclosure_019eb2c2-a4c8-79ae-a8d0-02babd8a01c9" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/FairValueDebtPortfolioDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#FairValueDebtPortfolioDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/FairValueDebtPortfolioDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-76df-96ba-958d3b7fa2ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-77e1-8206-741468ab0f29" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-76df-96ba-958d3b7fa2ad" xlink:to="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-77e1-8206-741468ab0f29" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7bbb-aa0e-3c0a90c19dba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-77e1-8206-741468ab0f29" xlink:to="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7bbb-aa0e-3c0a90c19dba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7bbb-aa0e-3c0a90c19dba_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7bbb-aa0e-3c0a90c19dba" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7bbb-aa0e-3c0a90c19dba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-71c6-bd2c-afdca5b43c3a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7bbb-aa0e-3c0a90c19dba" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-71c6-bd2c-afdca5b43c3a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_UnsecuredSeniorNotesMember_019eb2c2-a4c8-7832-bd2c-45d3c77e2f65" xlink:href="sndr-20260630.xsd#sndr_UnsecuredSeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-71c6-bd2c-afdca5b43c3a" xlink:to="loc_sndr_UnsecuredSeniorNotesMember_019eb2c2-a4c8-7832-bd2c-45d3c77e2f65" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019eb2c2-a4c8-71db-8fd6-1585a57a780c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-77e1-8206-741468ab0f29" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019eb2c2-a4c8-71db-8fd6-1585a57a780c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019eb2c2-a4c8-71db-8fd6-1585a57a780c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019eb2c2-a4c8-71db-8fd6-1585a57a780c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019eb2c2-a4c8-71db-8fd6-1585a57a780c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019eb2c2-a4c8-73c5-91e8-fe39b831277d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019eb2c2-a4c8-71db-8fd6-1585a57a780c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019eb2c2-a4c8-73c5-91e8-fe39b831277d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019eb2c2-a4c8-740b-9d54-723a9e7a2e0f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019eb2c2-a4c8-73c5-91e8-fe39b831277d" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019eb2c2-a4c8-740b-9d54-723a9e7a2e0f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFairValue_019eb2c2-a4c8-71d5-92ef-74b0fa01311a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-76df-96ba-958d3b7fa2ad" xlink:to="loc_us-gaap_DebtInstrumentFairValue_019eb2c2-a4c8-71d5-92ef-74b0fa01311a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019eb2c2-a4c8-7d92-8ba6-cee00fed0d29" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-76df-96ba-958d3b7fa2ad" xlink:to="loc_us-gaap_LongTermDebt_019eb2c2-a4c8-7d92-8ba6-cee00fed0d29" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/InvestmentsNarrativeDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#InvestmentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/InvestmentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7399-9a53-34655b7c4b22" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable_019eb2c2-a4c8-7c1b-9801-18c514c4aa8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7399-9a53-34655b7c4b22" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable_019eb2c2-a4c8-7c1b-9801-18c514c4aa8a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_019eb2c2-a4c8-7f20-b817-ec27bfc49c25" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable_019eb2c2-a4c8-7c1b-9801-18c514c4aa8a" xlink:to="loc_srt_OwnershipAxis_019eb2c2-a4c8-7f20-b817-ec27bfc49c25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019eb2c2-a4c8-7f20-b817-ec27bfc49c25_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_019eb2c2-a4c8-7f20-b817-ec27bfc49c25" xlink:to="loc_srt_OwnershipDomain_019eb2c2-a4c8-7f20-b817-ec27bfc49c25_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019eb2c2-a4c8-73f3-974c-8c70ed18d8c6" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_019eb2c2-a4c8-7f20-b817-ec27bfc49c25" xlink:to="loc_srt_OwnershipDomain_019eb2c2-a4c8-73f3-974c-8c70ed18d8c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_MasteryLogisticsMember_019eb2c2-a4c8-77d1-bf57-0bd15e37b4f2" xlink:href="sndr-20260630.xsd#sndr_MasteryLogisticsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_019eb2c2-a4c8-73f3-974c-8c70ed18d8c6" xlink:to="loc_sndr_MasteryLogisticsMember_019eb2c2-a4c8-77d1-bf57-0bd15e37b4f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_PlatformScienceInc.Member_019eb2c2-a4c8-7a54-a6dd-1a230fb4c0b9" xlink:href="sndr-20260630.xsd#sndr_PlatformScienceInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_019eb2c2-a4c8-73f3-974c-8c70ed18d8c6" xlink:to="loc_sndr_PlatformScienceInc.Member_019eb2c2-a4c8-7a54-a6dd-1a230fb4c0b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_019eb2c2-a4c8-7096-ab33-e3d8428ff5f4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable_019eb2c2-a4c8-7c1b-9801-18c514c4aa8a" xlink:to="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_019eb2c2-a4c8-7096-ab33-e3d8428ff5f4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableTypeDomain_019eb2c2-a4c8-7096-ab33-e3d8428ff5f4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReceivableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_019eb2c2-a4c8-7096-ab33-e3d8428ff5f4" xlink:to="loc_us-gaap_ReceivableTypeDomain_019eb2c2-a4c8-7096-ab33-e3d8428ff5f4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableTypeDomain_019eb2c2-a4c8-73b9-ab1d-f2e721bfa1c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReceivableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_019eb2c2-a4c8-7096-ab33-e3d8428ff5f4" xlink:to="loc_us-gaap_ReceivableTypeDomain_019eb2c2-a4c8-73b9-ab1d-f2e721bfa1c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableMember_019eb2c2-a4c8-711d-b4a0-2f3820f3c9b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivableTypeDomain_019eb2c2-a4c8-73b9-ab1d-f2e721bfa1c8" xlink:to="loc_us-gaap_NotesReceivableMember_019eb2c2-a4c8-711d-b4a0-2f3820f3c9b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_ShortTermNoteReceivableMember_019eb2c2-a4c8-7bbc-a220-439abbec9dfa" xlink:href="sndr-20260630.xsd#sndr_ShortTermNoteReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivableTypeDomain_019eb2c2-a4c8-73b9-ab1d-f2e721bfa1c8" xlink:to="loc_sndr_ShortTermNoteReceivableMember_019eb2c2-a4c8-7bbc-a220-439abbec9dfa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss_019eb2c2-a4c8-73b0-82cb-6b41dba139ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7399-9a53-34655b7c4b22" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss_019eb2c2-a4c8-73b0-82cb-6b41dba139ba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount_019eb2c2-a4c8-7d56-be1e-1a859b0ea3eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7399-9a53-34655b7c4b22" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount_019eb2c2-a4c8-7d56-be1e-1a859b0ea3eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesAndLoansReceivableGrossCurrent_019eb2c2-a4c8-75c1-845b-69676a3752a4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesAndLoansReceivableGrossCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7399-9a53-34655b7c4b22" xlink:to="loc_us-gaap_NotesAndLoansReceivableGrossCurrent_019eb2c2-a4c8-75c1-845b-69676a3752a4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesAndLoansReceivableGrossNoncurrent_019eb2c2-a4c8-75b1-b454-f78bbc402976" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesAndLoansReceivableGrossNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7399-9a53-34655b7c4b22" xlink:to="loc_us-gaap_NotesAndLoansReceivableGrossNoncurrent_019eb2c2-a4c8-75b1-b454-f78bbc402976" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_FinancingReceivableIncludingAccruedInterest_019eb2c2-a4c8-7d55-8c67-2252a7d9c49c" xlink:href="sndr-20260630.xsd#sndr_FinancingReceivableIncludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7399-9a53-34655b7c4b22" xlink:to="loc_sndr_FinancingReceivableIncludingAccruedInterest_019eb2c2-a4c8-7d55-8c67-2252a7d9c49c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndOtherIncome_019eb2c2-a4c8-707b-aac0-b59f5fa2cc53" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestAndOtherIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7399-9a53-34655b7c4b22" xlink:to="loc_us-gaap_InterestAndOtherIncome_019eb2c2-a4c8-707b-aac0-b59f5fa2cc53" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/InvestmentsScheduleofMarketableSecuritiesDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#InvestmentsScheduleofMarketableSecuritiesDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/InvestmentsScheduleofMarketableSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019eb2c2-a4c8-72e2-b9c1-1c75e84b2845" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019eb2c2-a4c8-7eca-a50a-11ebd82ec127" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019eb2c2-a4c8-72e2-b9c1-1c75e84b2845" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019eb2c2-a4c8-7eca-a50a-11ebd82ec127" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019eb2c2-a4c8-7741-ad04-8926978d5205" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019eb2c2-a4c8-7eca-a50a-11ebd82ec127" xlink:to="loc_srt_RangeAxis_019eb2c2-a4c8-7741-ad04-8926978d5205" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019eb2c2-a4c8-7741-ad04-8926978d5205_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019eb2c2-a4c8-7741-ad04-8926978d5205" xlink:to="loc_srt_RangeMember_019eb2c2-a4c8-7741-ad04-8926978d5205_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019eb2c2-a4c8-751b-ab1d-873a6d6f2a0e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019eb2c2-a4c8-7741-ad04-8926978d5205" xlink:to="loc_srt_RangeMember_019eb2c2-a4c8-751b-ab1d-873a6d6f2a0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019eb2c2-a4c8-70d5-9fd6-45e02a6e8e7d" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019eb2c2-a4c8-751b-ab1d-873a6d6f2a0e" xlink:to="loc_srt_MinimumMember_019eb2c2-a4c8-70d5-9fd6-45e02a6e8e7d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019eb2c2-a4c8-7f6b-b53e-700baa2c67e4" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019eb2c2-a4c8-751b-ab1d-873a6d6f2a0e" xlink:to="loc_srt_MaximumMember_019eb2c2-a4c8-7f6b-b53e-700baa2c67e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_019eb2c2-a4c8-79ff-a86f-3d167a90cf71" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfFinancialPositionLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019eb2c2-a4c8-7eca-a50a-11ebd82ec127" xlink:to="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_019eb2c2-a4c8-79ff-a86f-3d167a90cf71" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019eb2c2-a4c8-74db-8414-e900a2405773" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019eb2c2-a4c8-7eca-a50a-11ebd82ec127" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019eb2c2-a4c8-74db-8414-e900a2405773" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-74db-8414-e900a2405773_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019eb2c2-a4c8-74db-8414-e900a2405773" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-74db-8414-e900a2405773_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-7437-894a-c54e3f0531a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019eb2c2-a4c8-74db-8414-e900a2405773" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-7437-894a-c54e3f0531a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasuryAndGovernmentMember_019eb2c2-a4c8-7377-862f-93f014d41a8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasuryAndGovernmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-7437-894a-c54e3f0531a3" xlink:to="loc_us-gaap_USTreasuryAndGovernmentMember_019eb2c2-a4c8-7377-862f-93f014d41a8a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_019eb2c2-a4c8-70a5-afef-5865d2363da1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-7437-894a-c54e3f0531a3" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_019eb2c2-a4c8-70a5-afef-5865d2363da1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_019eb2c2-a4c8-7dbe-92f5-846d936a2f04" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-7437-894a-c54e3f0531a3" xlink:to="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_019eb2c2-a4c8-7dbe-92f5-846d936a2f04" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityDate_019eb2c2-a4c8-7ae5-9425-ac6b139a8765" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleMaturityDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019eb2c2-a4c8-72e2-b9c1-1c75e84b2845" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityDate_019eb2c2-a4c8-7ae5-9425-ac6b139a8765" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019eb2c2-a4c8-759d-beac-94173dc20676" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019eb2c2-a4c8-72e2-b9c1-1c75e84b2845" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019eb2c2-a4c8-759d-beac-94173dc20676" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019eb2c2-a4c8-7e5c-b592-baf2ca91cf50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019eb2c2-a4c8-72e2-b9c1-1c75e84b2845" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019eb2c2-a4c8-7e5c-b592-baf2ca91cf50" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/InvestmentsScheduleofMarketableSecuritiesDetails_1" xlink:type="simple" xlink:href="sndr-20260630.xsd#InvestmentsScheduleofMarketableSecuritiesDetails_1"/>
  <link:definitionLink xlink:role="http://schneider.com/role/InvestmentsScheduleofMarketableSecuritiesDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019eb2c2-a4c8-72e2-b9c1-1c75e84b2845" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019eb2c2-a4c8-7eca-a50a-11ebd82ec127" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019eb2c2-a4c8-72e2-b9c1-1c75e84b2845" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019eb2c2-a4c8-7eca-a50a-11ebd82ec127" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019eb2c2-a4c8-7741-ad04-8926978d5205" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019eb2c2-a4c8-7eca-a50a-11ebd82ec127" xlink:to="loc_srt_RangeAxis_019eb2c2-a4c8-7741-ad04-8926978d5205" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019eb2c2-a4c8-7741-ad04-8926978d5205_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019eb2c2-a4c8-7741-ad04-8926978d5205" xlink:to="loc_srt_RangeMember_019eb2c2-a4c8-7741-ad04-8926978d5205_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019eb2c2-a4c8-751b-ab1d-873a6d6f2a0e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019eb2c2-a4c8-7741-ad04-8926978d5205" xlink:to="loc_srt_RangeMember_019eb2c2-a4c8-751b-ab1d-873a6d6f2a0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019eb2c2-a4c8-70d5-9fd6-45e02a6e8e7d" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019eb2c2-a4c8-751b-ab1d-873a6d6f2a0e" xlink:to="loc_srt_MinimumMember_019eb2c2-a4c8-70d5-9fd6-45e02a6e8e7d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019eb2c2-a4c8-7f6b-b53e-700baa2c67e4" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019eb2c2-a4c8-751b-ab1d-873a6d6f2a0e" xlink:to="loc_srt_MaximumMember_019eb2c2-a4c8-7f6b-b53e-700baa2c67e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019eb2c2-a4c8-74db-8414-e900a2405773" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_019eb2c2-a4c8-7eca-a50a-11ebd82ec127" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019eb2c2-a4c8-74db-8414-e900a2405773" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-74db-8414-e900a2405773_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019eb2c2-a4c8-74db-8414-e900a2405773" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-74db-8414-e900a2405773_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-7437-894a-c54e3f0531a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019eb2c2-a4c8-74db-8414-e900a2405773" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-7437-894a-c54e3f0531a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasuryAndGovernmentMember_019eb2c2-a4c8-7377-862f-93f014d41a8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasuryAndGovernmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-7437-894a-c54e3f0531a3" xlink:to="loc_us-gaap_USTreasuryAndGovernmentMember_019eb2c2-a4c8-7377-862f-93f014d41a8a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_019eb2c2-a4c8-70a5-afef-5865d2363da1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-7437-894a-c54e3f0531a3" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_019eb2c2-a4c8-70a5-afef-5865d2363da1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_019eb2c2-a4c8-7dbe-92f5-846d936a2f04" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019eb2c2-a4c8-7437-894a-c54e3f0531a3" xlink:to="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_019eb2c2-a4c8-7dbe-92f5-846d936a2f04" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityDate_019eb2c2-a4c8-7ae5-9425-ac6b139a8765" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleMaturityDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019eb2c2-a4c8-72e2-b9c1-1c75e84b2845" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleMaturityDate_019eb2c2-a4c8-7ae5-9425-ac6b139a8765" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019eb2c2-a4c8-759d-beac-94173dc20676" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019eb2c2-a4c8-72e2-b9c1-1c75e84b2845" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019eb2c2-a4c8-759d-beac-94173dc20676" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019eb2c2-a4c8-7e5c-b592-baf2ca91cf50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019eb2c2-a4c8-72e2-b9c1-1c75e84b2845" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019eb2c2-a4c8-7e5c-b592-baf2ca91cf50" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/InvestmentsEquityInvestmentswithoutReadilyDeterminableFairValuesDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#InvestmentsEquityInvestmentswithoutReadilyDeterminableFairValuesDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/InvestmentsEquityInvestmentswithoutReadilyDeterminableFairValuesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7d3b-8d98-36eeace5c750" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable_019eb2c2-a4c8-746c-817b-c6df1408b3e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7d3b-8d98-36eeace5c750" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable_019eb2c2-a4c8-746c-817b-c6df1408b3e3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_019eb2c2-a4c8-73f0-93a0-a97eeba9fb53" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable_019eb2c2-a4c8-746c-817b-c6df1408b3e3" xlink:to="loc_srt_OwnershipAxis_019eb2c2-a4c8-73f0-93a0-a97eeba9fb53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019eb2c2-a4c8-73f0-93a0-a97eeba9fb53_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_019eb2c2-a4c8-73f0-93a0-a97eeba9fb53" xlink:to="loc_srt_OwnershipDomain_019eb2c2-a4c8-73f0-93a0-a97eeba9fb53_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_019eb2c2-a4c8-7fce-b884-87c5fca81ac2" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_019eb2c2-a4c8-73f0-93a0-a97eeba9fb53" xlink:to="loc_srt_OwnershipDomain_019eb2c2-a4c8-7fce-b884-87c5fca81ac2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_MasteryLogisticsMember_019eb2c2-a4c8-7bb0-8eb2-f275f08134e7" xlink:href="sndr-20260630.xsd#sndr_MasteryLogisticsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_019eb2c2-a4c8-7fce-b884-87c5fca81ac2" xlink:to="loc_sndr_MasteryLogisticsMember_019eb2c2-a4c8-7bb0-8eb2-f275f08134e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_019eb2c2-a4c8-77d3-860a-87c8313d81eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable_019eb2c2-a4c8-746c-817b-c6df1408b3e3" xlink:to="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_019eb2c2-a4c8-77d3-860a-87c8313d81eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableTypeDomain_019eb2c2-a4c8-77d3-860a-87c8313d81eb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReceivableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_019eb2c2-a4c8-77d3-860a-87c8313d81eb" xlink:to="loc_us-gaap_ReceivableTypeDomain_019eb2c2-a4c8-77d3-860a-87c8313d81eb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableTypeDomain_019eb2c2-a4c8-7417-a551-8460111e7017" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReceivableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_019eb2c2-a4c8-77d3-860a-87c8313d81eb" xlink:to="loc_us-gaap_ReceivableTypeDomain_019eb2c2-a4c8-7417-a551-8460111e7017" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableMember_019eb2c2-a4c8-79b5-b971-c8a57cbf58a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivableTypeDomain_019eb2c2-a4c8-7417-a551-8460111e7017" xlink:to="loc_us-gaap_NotesReceivableMember_019eb2c2-a4c8-79b5-b971-c8a57cbf58a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_EquitySecuritiesWithoutReadilyDeterminableFairValueCurrentPeriodAmount_019fa433-7c91-702f-a258-148f60cd0e89" xlink:href="sndr-20260630.xsd#sndr_EquitySecuritiesWithoutReadilyDeterminableFairValueCurrentPeriodAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7d3b-8d98-36eeace5c750" xlink:to="loc_sndr_EquitySecuritiesWithoutReadilyDeterminableFairValueCurrentPeriodAmount_019fa433-7c91-702f-a258-148f60cd0e89" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentAnnualAmount_019eb2c2-a4c8-7f27-8449-9ec884af24e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentAnnualAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7d3b-8d98-36eeace5c750" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentAnnualAmount_019eb2c2-a4c8-7f27-8449-9ec884af24e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueDownwardPriceAdjustmentAnnualAmount_019eb2c2-a4c8-72f7-a590-61e53113fabd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueDownwardPriceAdjustmentAnnualAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019eb2c2-a4c8-7d3b-8d98-36eeace5c750" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueDownwardPriceAdjustmentAnnualAmount_019eb2c2-a4c8-72f7-a590-61e53113fabd" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/InvestmentsInvestmentinTuSimpleDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#InvestmentsInvestmentinTuSimpleDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/InvestmentsInvestmentinTuSimpleDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019eb2c2-a4c8-7e68-a1f2-cbf28de3ff2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_019eb2c2-a4c8-7f46-8cd9-33b73b2f3000" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019eb2c2-a4c8-7e68-a1f2-cbf28de3ff2a" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_019eb2c2-a4c8-7f46-8cd9-33b73b2f3000" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019eb2c2-a4c8-7728-8827-b7ebc48e5044" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_019eb2c2-a4c8-7f46-8cd9-33b73b2f3000" xlink:to="loc_us-gaap_InvestmentTypeAxis_019eb2c2-a4c8-7728-8827-b7ebc48e5044" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019eb2c2-a4c8-7728-8827-b7ebc48e5044_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019eb2c2-a4c8-7728-8827-b7ebc48e5044" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019eb2c2-a4c8-7728-8827-b7ebc48e5044_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019eb2c2-a4c8-7023-8c81-1918ba33a702" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019eb2c2-a4c8-7728-8827-b7ebc48e5044" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019eb2c2-a4c8-7023-8c81-1918ba33a702" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiCost_019eb2c2-a4c8-7a4d-920c-bd462b7695a4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesFvNiCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019eb2c2-a4c8-7e68-a1f2-cbf28de3ff2a" xlink:to="loc_us-gaap_EquitySecuritiesFvNiCost_019eb2c2-a4c8-7a4d-920c-bd462b7695a4" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/InvestmentsEquityMethodInvestmentDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#InvestmentsEquityMethodInvestmentDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/InvestmentsEquityMethodInvestmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019eb2c2-a4c8-7f41-8b2b-17b70c0bf37e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_019eb2c2-a4c8-7c5e-a168-7e0172145dac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019eb2c2-a4c8-7f41-8b2b-17b70c0bf37e" xlink:to="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_019eb2c2-a4c8-7c5e-a168-7e0172145dac" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019eb2c2-a4c8-7de6-b40d-7719a9cc3d62" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable_019eb2c2-a4c8-7c5e-a168-7e0172145dac" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019eb2c2-a4c8-7de6-b40d-7719a9cc3d62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019eb2c2-a4c8-7de6-b40d-7719a9cc3d62_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019eb2c2-a4c8-7de6-b40d-7719a9cc3d62" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019eb2c2-a4c8-7de6-b40d-7719a9cc3d62_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019eb2c2-a4c8-7e81-831f-78c75718ff85" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019eb2c2-a4c8-7de6-b40d-7719a9cc3d62" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019eb2c2-a4c8-7e81-831f-78c75718ff85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_Scope23Member_019eb2c2-a4c8-7e8c-bf05-296f60c89b95" xlink:href="sndr-20260630.xsd#sndr_Scope23Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019eb2c2-a4c8-7e81-831f-78c75718ff85" xlink:to="loc_sndr_Scope23Member_019eb2c2-a4c8-7e8c-bf05-296f60c89b95" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentAggregateCost_019eb2c2-a4c8-7089-b6bb-851297541272" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentAggregateCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019eb2c2-a4c8-7f41-8b2b-17b70c0bf37e" xlink:to="loc_us-gaap_EquityMethodInvestmentAggregateCost_019eb2c2-a4c8-7089-b6bb-851297541272" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019eb2c2-a4c8-7c64-9567-cbfef0d0de39" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019eb2c2-a4c8-7f41-8b2b-17b70c0bf37e" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019eb2c2-a4c8-7c64-9567-cbfef0d0de39" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_019eb2c2-a4c8-78a6-9156-b3daca8309a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems_019eb2c2-a4c8-7f41-8b2b-17b70c0bf37e" xlink:to="loc_us-gaap_EquityMethodInvestments_019eb2c2-a4c8-78a6-9156-b3daca8309a0" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/IntangiblesScheduleofChangesinCarryingAmountofIntangiblesDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#IntangiblesScheduleofChangesinCarryingAmountofIntangiblesDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/IntangiblesScheduleofChangesinCarryingAmountofIntangiblesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7649-aebb-f009a8cab776" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7c80-aa8e-39306c144a9c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7649-aebb-f009a8cab776" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7c80-aa8e-39306c144a9c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019eb2c2-a4c8-7a79-b685-a09a56065187" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7c80-aa8e-39306c144a9c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019eb2c2-a4c8-7a79-b685-a09a56065187" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-7a79-b685-a09a56065187_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019eb2c2-a4c8-7a79-b685-a09a56065187" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-7a79-b685-a09a56065187_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-71ca-9824-3e3296b73a2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019eb2c2-a4c8-7a79-b685-a09a56065187" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-71ca-9824-3e3296b73a2a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019eb2c2-a4c8-71b3-88fc-cc6ea9818410" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-71ca-9824-3e3296b73a2a" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019eb2c2-a4c8-71b3-88fc-cc6ea9818410" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksMember_019eb2c2-a4c8-77dd-bd71-fb6b38aae761" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TrademarksMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-71ca-9824-3e3296b73a2a" xlink:to="loc_us-gaap_TrademarksMember_019eb2c2-a4c8-77dd-bd71-fb6b38aae761" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncompeteAgreementsMember_019eb2c2-a4c8-7df1-8dd8-cdc5162fd03c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncompeteAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-71ca-9824-3e3296b73a2a" xlink:to="loc_us-gaap_NoncompeteAgreementsMember_019eb2c2-a4c8-7df1-8dd8-cdc5162fd03c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7d04-b32c-2b1bc5cf18ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7c80-aa8e-39306c144a9c" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7d04-b32c-2b1bc5cf18ea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7d04-b32c-2b1bc5cf18ea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7d04-b32c-2b1bc5cf18ea" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7d04-b32c-2b1bc5cf18ea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7a9b-9806-93c8aae6c435" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7d04-b32c-2b1bc5cf18ea" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7a9b-9806-93c8aae6c435" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-71f2-aade-d64b841e350c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7c80-aa8e-39306c144a9c" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-71f2-aade-d64b841e350c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-71f2-aade-d64b841e350c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-71f2-aade-d64b841e350c" xlink:to="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-71f2-aade-d64b841e350c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7860-b7a2-eaf8f6e0f14f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-71f2-aade-d64b841e350c" xlink:to="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7860-b7a2-eaf8f6e0f14f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_TruckloadMember_019eb2c2-a4c8-757b-ba6b-81beb8beaaa5" xlink:href="sndr-20260630.xsd#sndr_TruckloadMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7860-b7a2-eaf8f6e0f14f" xlink:to="loc_sndr_TruckloadMember_019eb2c2-a4c8-757b-ba6b-81beb8beaaa5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_LogisticsMember_019eb2c2-a4c8-7b31-9fd4-71e37ab2aa01" xlink:href="sndr-20260630.xsd#sndr_LogisticsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7860-b7a2-eaf8f6e0f14f" xlink:to="loc_sndr_LogisticsMember_019eb2c2-a4c8-7b31-9fd4-71e37ab2aa01" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019eb2c2-a4c8-7f51-a123-8c3efa6f5d89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7649-aebb-f009a8cab776" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019eb2c2-a4c8-7f51-a123-8c3efa6f5d89" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019eb2c2-a4c8-7938-b907-8eea01bfa2d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7649-aebb-f009a8cab776" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019eb2c2-a4c8-7938-b907-8eea01bfa2d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019eb2c2-a4c8-7d20-bcca-c52ccf237997" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7649-aebb-f009a8cab776" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019eb2c2-a4c8-7d20-bcca-c52ccf237997" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/IntangiblesFutureAmortizationExpenseDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#IntangiblesFutureAmortizationExpenseDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/IntangiblesFutureAmortizationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7b6b-8618-a5f26296a83b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7be7-b555-cdae91119c0a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7b6b-8618-a5f26296a83b" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7be7-b555-cdae91119c0a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7d33-a261-70c6e959af39" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7be7-b555-cdae91119c0a" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7d33-a261-70c6e959af39" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7d33-a261-70c6e959af39_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7d33-a261-70c6e959af39" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7d33-a261-70c6e959af39_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7cef-b348-ab4d4e61fa6c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7d33-a261-70c6e959af39" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7cef-b348-ab4d4e61fa6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_019eb2c2-a4c8-72e1-8a96-5499983b0587" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7b6b-8618-a5f26296a83b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_019eb2c2-a4c8-72e1-8a96-5499983b0587" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_019eb2c2-a4c8-7dd0-842d-453a65f721f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7b6b-8618-a5f26296a83b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_019eb2c2-a4c8-7dd0-842d-453a65f721f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_019eb2c2-a4c8-7ea6-899a-301101f43086" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7b6b-8618-a5f26296a83b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_019eb2c2-a4c8-7ea6-899a-301101f43086" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_019eb2c2-a4c8-780e-9007-e741ac43da3d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7b6b-8618-a5f26296a83b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_019eb2c2-a4c8-780e-9007-e741ac43da3d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_019eb2c2-a4c8-7e32-bba3-d42bcf637a4e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7b6b-8618-a5f26296a83b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_019eb2c2-a4c8-7e32-bba3-d42bcf637a4e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_019eb2c2-a4c8-7069-b35e-3c57f8ab0fa2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7b6b-8618-a5f26296a83b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_019eb2c2-a4c8-7069-b35e-3c57f8ab0fa2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019eb2c2-a4c8-7011-9af6-0af0c321a7df" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7b6b-8618-a5f26296a83b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019eb2c2-a4c8-7011-9af6-0af0c321a7df" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/GoodwillAdditionalInformationDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#GoodwillAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/GoodwillAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_019eb2c2-a4c8-7f9c-9ce0-f7e946c68895" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_019eb2c2-a4c8-70ca-b9e9-91c4d08d91e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_019eb2c2-a4c8-7f9c-9ce0-f7e946c68895" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_019eb2c2-a4c8-70ca-b9e9-91c4d08d91e6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-7c25-a420-a92739182ae2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_019eb2c2-a4c8-70ca-b9e9-91c4d08d91e6" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-7c25-a420-a92739182ae2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7c25-a420-a92739182ae2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-7c25-a420-a92739182ae2" xlink:to="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7c25-a420-a92739182ae2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7b1c-ad32-c40b89d4544f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-7c25-a420-a92739182ae2" xlink:to="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7b1c-ad32-c40b89d4544f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_TruckloadMember_019eb2c2-a4c8-7315-a39c-35f130432f52" xlink:href="sndr-20260630.xsd#sndr_TruckloadMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7b1c-ad32-c40b89d4544f" xlink:to="loc_sndr_TruckloadMember_019eb2c2-a4c8-7315-a39c-35f130432f52" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_LogisticsMember_019eb2c2-a4c8-767f-9d49-257f531021ae" xlink:href="sndr-20260630.xsd#sndr_LogisticsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7b1c-ad32-c40b89d4544f" xlink:to="loc_sndr_LogisticsMember_019eb2c2-a4c8-767f-9d49-257f531021ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-76fe-b88d-80a7dd4619ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_019eb2c2-a4c8-70ca-b9e9-91c4d08d91e6" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-76fe-b88d-80a7dd4619ba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-76fe-b88d-80a7dd4619ba_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-76fe-b88d-80a7dd4619ba" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-76fe-b88d-80a7dd4619ba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7126-8f83-520ac5a53b30" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-76fe-b88d-80a7dd4619ba" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7126-8f83-520ac5a53b30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementAxis_019eb2c2-a4c8-790c-b190-8e93cc1f4bc1" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_019eb2c2-a4c8-70ca-b9e9-91c4d08d91e6" xlink:to="loc_srt_RestatementAxis_019eb2c2-a4c8-790c-b190-8e93cc1f4bc1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_019eb2c2-a4c8-790c-b190-8e93cc1f4bc1_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RestatementAxis_019eb2c2-a4c8-790c-b190-8e93cc1f4bc1" xlink:to="loc_srt_RestatementDomain_019eb2c2-a4c8-790c-b190-8e93cc1f4bc1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_019eb2c2-a4c8-7688-8e2f-7ac3490c70d6" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RestatementAxis_019eb2c2-a4c8-790c-b190-8e93cc1f4bc1" xlink:to="loc_srt_RestatementDomain_019eb2c2-a4c8-7688-8e2f-7ac3490c70d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019eb2c2-a4c8-78e9-9d4f-7fa4f125a6b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019eb2c2-a4c8-7f9c-9ce0-f7e946c68895" xlink:to="loc_us-gaap_Goodwill_019eb2c2-a4c8-78e9-9d4f-7fa4f125a6b4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_019eb2c2-a4c8-72df-8a0b-8bf9d9eeb295" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019eb2c2-a4c8-7f9c-9ce0-f7e946c68895" xlink:to="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_019eb2c2-a4c8-72df-8a0b-8bf9d9eeb295" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/IntangiblesAdditionalInformationDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#IntangiblesAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/IntangiblesAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7e57-b16a-9a12286fc567" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7426-abb0-048ce5431cab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7e57-b16a-9a12286fc567" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7426-abb0-048ce5431cab" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7cbc-8da1-f74a3149d455" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7426-abb0-048ce5431cab" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7cbc-8da1-f74a3149d455" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7cbc-8da1-f74a3149d455_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7cbc-8da1-f74a3149d455" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-7cbc-8da1-f74a3149d455_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-79f3-995c-fb3dafed824f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019eb2c2-a4c8-7cbc-8da1-f74a3149d455" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019eb2c2-a4c8-79f3-995c-fb3dafed824f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019eb2c2-a4c8-7d49-a0ab-55e7f1511091" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019eb2c2-a4c8-7426-abb0-048ce5431cab" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019eb2c2-a4c8-7d49-a0ab-55e7f1511091" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-7d49-a0ab-55e7f1511091_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019eb2c2-a4c8-7d49-a0ab-55e7f1511091" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-7d49-a0ab-55e7f1511091_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-7f7a-95ca-bffd1e42de3d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019eb2c2-a4c8-7d49-a0ab-55e7f1511091" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-7f7a-95ca-bffd1e42de3d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019eb2c2-a4c8-7bef-8f76-4e71015a197c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-7f7a-95ca-bffd1e42de3d" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019eb2c2-a4c8-7bef-8f76-4e71015a197c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncompeteAgreementsMember_019eb2c2-a4c8-7b5c-be27-1989ac2fd213" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncompeteAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019eb2c2-a4c8-7f7a-95ca-bffd1e42de3d" xlink:to="loc_us-gaap_NoncompeteAgreementsMember_019eb2c2-a4c8-7b5c-be27-1989ac2fd213" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_019eb2c2-a4c8-74e9-9cfb-92fca0a11b90" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019eb2c2-a4c8-7e57-b16a-9a12286fc567" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_019eb2c2-a4c8-74e9-9cfb-92fca0a11b90" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/DebtandCreditFacilitiesSummaryofDebtDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#DebtandCreditFacilitiesSummaryofDebtDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/DebtandCreditFacilitiesSummaryofDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7b5c-bd47-8aac283ae0b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-7d78-b244-ca6fac4618c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7b5c-bd47-8aac283ae0b8" xlink:to="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-7d78-b244-ca6fac4618c8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7c7a-97a7-76aba5f95aa4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-7d78-b244-ca6fac4618c8" xlink:to="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7c7a-97a7-76aba5f95aa4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7c7a-97a7-76aba5f95aa4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7c7a-97a7-76aba5f95aa4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7c7a-97a7-76aba5f95aa4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7e72-a64c-b54c47ce98b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7c7a-97a7-76aba5f95aa4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7e72-a64c-b54c47ce98b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_UnsecuredSeniorNotesMember_019eb2c2-a4c8-7ae2-82b5-9661e0dde490" xlink:href="sndr-20260630.xsd#sndr_UnsecuredSeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7e72-a64c-b54c47ce98b2" xlink:to="loc_sndr_UnsecuredSeniorNotesMember_019eb2c2-a4c8-7ae2-82b5-9661e0dde490" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_CreditFacilityMember_019eb2c2-a4c8-74df-a383-7bd02d057f64" xlink:href="sndr-20260630.xsd#sndr_CreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7e72-a64c-b54c47ce98b2" xlink:to="loc_sndr_CreditFacilityMember_019eb2c2-a4c8-74df-a383-7bd02d057f64" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_ReceivablesPurchaseAgreementMember_019eb2c2-a4c8-7fb6-983a-b09419d4837c" xlink:href="sndr-20260630.xsd#sndr_ReceivablesPurchaseAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7e72-a64c-b54c47ce98b2" xlink:to="loc_sndr_ReceivablesPurchaseAgreementMember_019eb2c2-a4c8-7fb6-983a-b09419d4837c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_DelayedTermLoanFacilitiesMember_019eb2c2-a4c8-7812-8a47-ec968dc5d71b" xlink:href="sndr-20260630.xsd#sndr_DelayedTermLoanFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7e72-a64c-b54c47ce98b2" xlink:to="loc_sndr_DelayedTermLoanFacilitiesMember_019eb2c2-a4c8-7812-8a47-ec968dc5d71b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019eb2c2-a4c8-776c-a803-be2897121cf9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-7d78-b244-ca6fac4618c8" xlink:to="loc_srt_RangeAxis_019eb2c2-a4c8-776c-a803-be2897121cf9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019eb2c2-a4c8-776c-a803-be2897121cf9_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019eb2c2-a4c8-776c-a803-be2897121cf9" xlink:to="loc_srt_RangeMember_019eb2c2-a4c8-776c-a803-be2897121cf9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019eb2c2-a4c8-77ea-8125-4c6408fbd6b9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019eb2c2-a4c8-776c-a803-be2897121cf9" xlink:to="loc_srt_RangeMember_019eb2c2-a4c8-77ea-8125-4c6408fbd6b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019eb2c2-a4c8-78e3-a1ca-a8d62e599efe" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019eb2c2-a4c8-77ea-8125-4c6408fbd6b9" xlink:to="loc_srt_MinimumMember_019eb2c2-a4c8-78e3-a1ca-a8d62e599efe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_DebtInstrumentMaturityYear_019eb2c2-a4c8-7ac6-8424-f9ff53f7380b" xlink:href="sndr-20260630.xsd#sndr_DebtInstrumentMaturityYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7b5c-bd47-8aac283ae0b8" xlink:to="loc_sndr_DebtInstrumentMaturityYear_019eb2c2-a4c8-7ac6-8424-f9ff53f7380b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFrequencyOfPeriodicPayment_019eb2c2-a4c8-72ec-9f94-1fb15d473a38" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFrequencyOfPeriodicPayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7b5c-bd47-8aac283ae0b8" xlink:to="loc_us-gaap_DebtInstrumentFrequencyOfPeriodicPayment_019eb2c2-a4c8-72ec-9f94-1fb15d473a38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtWeightedAverageInterestRate_019eb2c2-a4c8-75c4-9c7f-0026a424cf7f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7b5c-bd47-8aac283ae0b8" xlink:to="loc_us-gaap_LongtermDebtWeightedAverageInterestRate_019eb2c2-a4c8-75c4-9c7f-0026a424cf7f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019eb2c2-a4c8-7b0f-961c-3a0ba88bd00e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7b5c-bd47-8aac283ae0b8" xlink:to="loc_us-gaap_LongTermDebt_019eb2c2-a4c8-7b0f-961c-3a0ba88bd00e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_019eb2c2-a4c8-7843-a973-5db576c140b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7b5c-bd47-8aac283ae0b8" xlink:to="loc_us-gaap_LongTermDebtCurrent_019eb2c2-a4c8-7843-a973-5db576c140b9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_019eb2c2-a4c8-7f37-bd0f-3a32d94cafec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7b5c-bd47-8aac283ae0b8" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_019eb2c2-a4c8-7f37-bd0f-3a32d94cafec" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019eb2c2-a4c8-7010-8e9c-6610f9a5a961" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7b5c-bd47-8aac283ae0b8" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_019eb2c2-a4c8-7010-8e9c-6610f9a5a961" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtLongtermAndShorttermCombinedAmount_019eb2c2-a4c8-7cf7-8859-a0ea8171ad9c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtLongtermAndShorttermCombinedAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7b5c-bd47-8aac283ae0b8" xlink:to="loc_us-gaap_DebtLongtermAndShorttermCombinedAmount_019eb2c2-a4c8-7cf7-8859-a0ea8171ad9c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_019eb2c2-a4c8-7d76-8836-785b1fb8f9a9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7b5c-bd47-8aac283ae0b8" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_019eb2c2-a4c8-7d76-8836-785b1fb8f9a9" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/DebtandCreditFacilitiesAdditionalInformationDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#DebtandCreditFacilitiesAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/DebtandCreditFacilitiesAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7e36-9ecc-81f850a11b4f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-7a60-8408-ad1345a337d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7e36-9ecc-81f850a11b4f" xlink:to="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-7a60-8408-ad1345a337d6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7a6d-8151-421626061b98" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-7a60-8408-ad1345a337d6" xlink:to="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7a6d-8151-421626061b98" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7a6d-8151-421626061b98_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7a6d-8151-421626061b98" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7a6d-8151-421626061b98_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7a2e-9f3f-80afd04a6873" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019eb2c2-a4c8-7a6d-8151-421626061b98" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7a2e-9f3f-80afd04a6873" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_CreditFacilityMember_019eb2c2-a4c8-7a6d-b023-7a94e1b987d7" xlink:href="sndr-20260630.xsd#sndr_CreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7a2e-9f3f-80afd04a6873" xlink:to="loc_sndr_CreditFacilityMember_019eb2c2-a4c8-7a6d-b023-7a94e1b987d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_ReceivablesPurchaseAgreementMember_019eb2c2-a4c8-76c5-a72a-85d88d17418a" xlink:href="sndr-20260630.xsd#sndr_ReceivablesPurchaseAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7a2e-9f3f-80afd04a6873" xlink:to="loc_sndr_ReceivablesPurchaseAgreementMember_019eb2c2-a4c8-76c5-a72a-85d88d17418a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_DelayedTermLoanFacilitiesMember_019eb2c2-a4c8-7b29-9c0a-aaa3c6f5e8f5" xlink:href="sndr-20260630.xsd#sndr_DelayedTermLoanFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019eb2c2-a4c8-7a2e-9f3f-80afd04a6873" xlink:to="loc_sndr_DelayedTermLoanFacilitiesMember_019eb2c2-a4c8-7b29-9c0a-aaa3c6f5e8f5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019eb2c2-a4c8-78d4-8ba4-cfed230eb307" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-7a60-8408-ad1345a337d6" xlink:to="loc_us-gaap_CreditFacilityAxis_019eb2c2-a4c8-78d4-8ba4-cfed230eb307" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019eb2c2-a4c8-78d4-8ba4-cfed230eb307_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019eb2c2-a4c8-78d4-8ba4-cfed230eb307" xlink:to="loc_us-gaap_CreditFacilityDomain_019eb2c2-a4c8-78d4-8ba4-cfed230eb307_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019eb2c2-a4c8-7d5d-b25a-a0dfb33d0786" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019eb2c2-a4c8-78d4-8ba4-cfed230eb307" xlink:to="loc_us-gaap_CreditFacilityDomain_019eb2c2-a4c8-7d5d-b25a-a0dfb33d0786" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StandbyLettersOfCreditMember_019eb2c2-a4c8-776f-be20-e2592939a04e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StandbyLettersOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019eb2c2-a4c8-7d5d-b25a-a0dfb33d0786" xlink:to="loc_us-gaap_StandbyLettersOfCreditMember_019eb2c2-a4c8-776f-be20-e2592939a04e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_CreditFacilityMember_019eb2c2-a4c8-73e1-8cd3-cfabf63585ec" xlink:href="sndr-20260630.xsd#sndr_CreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019eb2c2-a4c8-7d5d-b25a-a0dfb33d0786" xlink:to="loc_sndr_CreditFacilityMember_019eb2c2-a4c8-73e1-8cd3-cfabf63585ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019eb2c2-a4c8-75ff-8962-ede02a462015" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019eb2c2-a4c8-7a60-8408-ad1345a337d6" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019eb2c2-a4c8-75ff-8962-ede02a462015" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019eb2c2-a4c8-75ff-8962-ede02a462015_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019eb2c2-a4c8-75ff-8962-ede02a462015" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019eb2c2-a4c8-75ff-8962-ede02a462015_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019eb2c2-a4c8-7f00-b79f-2bdf60483814" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019eb2c2-a4c8-75ff-8962-ede02a462015" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019eb2c2-a4c8-7f00-b79f-2bdf60483814" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019eb2c2-a4c8-7973-bd08-ef6f0eca7392" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7e36-9ecc-81f850a11b4f" xlink:to="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019eb2c2-a4c8-7973-bd08-ef6f0eca7392" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_CreditFacilityPotentialIncreaseAmount_019eb2c2-a4c8-7b87-b314-b15b0b789bdf" xlink:href="sndr-20260630.xsd#sndr_CreditFacilityPotentialIncreaseAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7e36-9ecc-81f850a11b4f" xlink:to="loc_sndr_CreditFacilityPotentialIncreaseAmount_019eb2c2-a4c8-7b87-b314-b15b0b789bdf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityExpirationDate1_019eb2c2-a4c8-77a8-ae9a-4cbdd28428a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityExpirationDate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7e36-9ecc-81f850a11b4f" xlink:to="loc_us-gaap_LineOfCreditFacilityExpirationDate1_019eb2c2-a4c8-77a8-ae9a-4cbdd28428a7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_019eb2c2-a4c8-7b1a-b135-2f842d62b3e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7e36-9ecc-81f850a11b4f" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_019eb2c2-a4c8-7b1a-b135-2f842d62b3e4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019eb2c2-a4c8-74af-a368-9b991998a201" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019eb2c2-a4c8-7e36-9ecc-81f850a11b4f" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019eb2c2-a4c8-74af-a368-9b991998a201" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/LeasesNarrativeDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#LeasesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/LeasesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_019eb2c2-a4c8-75ae-b345-9a92b201fa53" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_019eb2c2-a4c8-7f3c-9dc0-56930448d751" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019eb2c2-a4c8-75ae-b345-9a92b201fa53" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_019eb2c2-a4c8-7f3c-9dc0-56930448d751" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019eb2c2-a4c8-7608-8219-196a9b0c8fff" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_019eb2c2-a4c8-7f3c-9dc0-56930448d751" xlink:to="loc_srt_RangeAxis_019eb2c2-a4c8-7608-8219-196a9b0c8fff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019eb2c2-a4c8-7608-8219-196a9b0c8fff_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019eb2c2-a4c8-7608-8219-196a9b0c8fff" xlink:to="loc_srt_RangeMember_019eb2c2-a4c8-7608-8219-196a9b0c8fff_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019eb2c2-a4c8-7f54-8819-3d389700189e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019eb2c2-a4c8-7608-8219-196a9b0c8fff" xlink:to="loc_srt_RangeMember_019eb2c2-a4c8-7f54-8819-3d389700189e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019eb2c2-a4c8-7f18-8b80-96d11eb7d594" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019eb2c2-a4c8-7f54-8819-3d389700189e" xlink:to="loc_srt_MinimumMember_019eb2c2-a4c8-7f18-8b80-96d11eb7d594" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019eb2c2-a4c8-737f-aad1-e06f94fa8272" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019eb2c2-a4c8-7f54-8819-3d389700189e" xlink:to="loc_srt_MaximumMember_019eb2c2-a4c8-737f-aad1-e06f94fa8272" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_LesseeLeaseNotYetCommencedAmount_019eb2c2-a4c8-7228-9182-8366b11834d5" xlink:href="sndr-20260630.xsd#sndr_LesseeLeaseNotYetCommencedAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019eb2c2-a4c8-75ae-b345-9a92b201fa53" xlink:to="loc_sndr_LesseeLeaseNotYetCommencedAmount_019eb2c2-a4c8-7228-9182-8366b11834d5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_LesseeLeaseNotyetCommencedTermofContract_019eb2c2-a4c8-777d-88a3-ad21ded87862" xlink:href="sndr-20260630.xsd#sndr_LesseeLeaseNotyetCommencedTermofContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019eb2c2-a4c8-75ae-b345-9a92b201fa53" xlink:to="loc_sndr_LesseeLeaseNotyetCommencedTermofContract_019eb2c2-a4c8-777d-88a3-ad21ded87862" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorLeaseDescriptionLineItems_019eb2c2-a4c8-78ec-932b-561bcd1c831b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LessorLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorLeaseDescriptionTable_019eb2c2-a4c8-7a61-8ca2-3d25a52d7ca1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LessorLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LessorLeaseDescriptionLineItems_019eb2c2-a4c8-78ec-932b-561bcd1c831b" xlink:to="loc_us-gaap_LessorLeaseDescriptionTable_019eb2c2-a4c8-7a61-8ca2-3d25a52d7ca1" xlink:type="arc" order="2" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019eb2c2-a4c8-7f22-95dd-9d76e2266ca4" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LessorLeaseDescriptionTable_019eb2c2-a4c8-7a61-8ca2-3d25a52d7ca1" xlink:to="loc_srt_RangeAxis_019eb2c2-a4c8-7f22-95dd-9d76e2266ca4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019eb2c2-a4c8-7f22-95dd-9d76e2266ca4_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019eb2c2-a4c8-78f3-bfda-71c524167795" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019eb2c2-a4c8-74fe-95b0-35dafc6085db" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019eb2c2-a4c8-75ea-9e26-aef08bdc9465" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentAxis_019eb2c2-a4c8-7e5d-8778-989bc31fa391" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LessorLeaseDescriptionTable_019eb2c2-a4c8-7a61-8ca2-3d25a52d7ca1" xlink:to="loc_us-gaap_InternalCreditAssessmentAxis_019eb2c2-a4c8-7e5d-8778-989bc31fa391" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_019eb2c2-a4c8-7e5d-8778-989bc31fa391_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_019eb2c2-a4c8-7e5d-8778-989bc31fa391" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_019eb2c2-a4c8-7e5d-8778-989bc31fa391_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_019eb2c2-a4c8-7174-8cfc-932778207d13" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_019eb2c2-a4c8-7e5d-8778-989bc31fa391" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_019eb2c2-a4c8-7174-8cfc-932778207d13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_PastDueMember_019eb2c2-a4c8-70e2-bc11-5898cd432c05" xlink:href="sndr-20260630.xsd#sndr_PastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_019eb2c2-a4c8-7174-8cfc-932778207d13" xlink:to="loc_sndr_PastDueMember_019eb2c2-a4c8-70e2-bc11-5898cd432c05" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_019eb2c2-a4c8-7695-bcf6-856948962464" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LessorLeaseDescriptionTable_019eb2c2-a4c8-7a61-8ca2-3d25a52d7ca1" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_019eb2c2-a4c8-7695-bcf6-856948962464" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019eb2c2-a4c8-7695-bcf6-856948962464_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_019eb2c2-a4c8-7695-bcf6-856948962464" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019eb2c2-a4c8-7695-bcf6-856948962464_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019eb2c2-a4c8-7b6b-982b-5215d403d5fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_019eb2c2-a4c8-7695-bcf6-856948962464" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019eb2c2-a4c8-7b6b-982b-5215d403d5fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialAssetPastDueMember_019eb2c2-a4c8-72a5-8484-1054541a491b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialAssetPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019eb2c2-a4c8-7b6b-982b-5215d403d5fc" xlink:to="loc_us-gaap_FinancialAssetPastDueMember_019eb2c2-a4c8-72a5-8484-1054541a491b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorSalesTypeLeaseTermOfContract1_019eb2c2-a4c8-77b6-b149-291fe1244b4c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LessorSalesTypeLeaseTermOfContract1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LessorLeaseDescriptionLineItems_019eb2c2-a4c8-78ec-932b-561bcd1c831b" xlink:to="loc_us-gaap_LessorSalesTypeLeaseTermOfContract1_019eb2c2-a4c8-77b6-b149-291fe1244b4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesTypeLeaseNetInvestmentInLease_019eb2c2-a4c8-7162-a0c3-88f4de5cc39b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SalesTypeLeaseNetInvestmentInLease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LessorLeaseDescriptionLineItems_019eb2c2-a4c8-78ec-932b-561bcd1c831b" xlink:to="loc_us-gaap_SalesTypeLeaseNetInvestmentInLease_019eb2c2-a4c8-7162-a0c3-88f4de5cc39b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceived_019eb2c2-a4c8-77b4-a59f-9d919e257d55" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LessorLeaseDescriptionLineItems_019eb2c2-a4c8-78ec-932b-561bcd1c831b" xlink:to="loc_us-gaap_SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceived_019eb2c2-a4c8-77b4-a59f-9d919e257d55" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/CommonEquityScheduleofcommonsharesoutstandingDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#CommonEquityScheduleofcommonsharesoutstandingDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/CommonEquityScheduleofcommonsharesoutstandingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-71cb-9d76-fa6fd8993508" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019eb2c2-a4c8-78d1-93b5-78d8a02a56ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-71cb-9d76-fa6fd8993508" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019eb2c2-a4c8-78d1-93b5-78d8a02a56ab" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-722a-8dcd-50fb97ecce59" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019eb2c2-a4c8-78d1-93b5-78d8a02a56ab" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-722a-8dcd-50fb97ecce59" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-722a-8dcd-50fb97ecce59_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-722a-8dcd-50fb97ecce59" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-722a-8dcd-50fb97ecce59_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7199-8f88-6bb8aa4154da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-722a-8dcd-50fb97ecce59" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7199-8f88-6bb8aa4154da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019eb2c2-a4c8-7809-84ae-250956f986a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7199-8f88-6bb8aa4154da" xlink:to="loc_us-gaap_CommonClassAMember_019eb2c2-a4c8-7809-84ae-250956f986a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019eb2c2-a4c8-75f8-9fb2-0754116748b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7199-8f88-6bb8aa4154da" xlink:to="loc_us-gaap_CommonClassBMember_019eb2c2-a4c8-75f8-9fb2-0754116748b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019eb2c2-a4c8-7788-812b-e5e73f9ae957" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-71cb-9d76-fa6fd8993508" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019eb2c2-a4c8-7788-812b-e5e73f9ae957" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019eb2c2-a4c8-7aca-ae4d-a6a625114882" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-71cb-9d76-fa6fd8993508" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019eb2c2-a4c8-7aca-ae4d-a6a625114882" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_019eb2c2-a4c8-7e92-9641-d043921754b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-71cb-9d76-fa6fd8993508" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_019eb2c2-a4c8-7e92-9641-d043921754b1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_019fa4f7-c96e-7728-b4f8-355bdfa302ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-71cb-9d76-fa6fd8993508" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_019fa4f7-c96e-7728-b4f8-355bdfa302ad" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_019eb2c2-a4c8-793a-a569-0135af75d7b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-71cb-9d76-fa6fd8993508" xlink:to="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_019eb2c2-a4c8-793a-a569-0135af75d7b0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019eb2c2-a4c8-7074-8c52-6d0a412dc9e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/CommonEquityAdditionalInformationDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#CommonEquityAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/CommonEquityAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-72fe-bc0f-27803709c8dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019eb2c2-a4c8-7ec2-b50a-c8f5de4f0858" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-72fe-bc0f-27803709c8dc" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019eb2c2-a4c8-7ec2-b50a-c8f5de4f0858" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-7c1e-8b92-0dbd62df5956" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019eb2c2-a4c8-7ec2-b50a-c8f5de4f0858" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-7c1e-8b92-0dbd62df5956" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7c1e-8b92-0dbd62df5956_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-7c1e-8b92-0dbd62df5956" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-7c1e-8b92-0dbd62df5956_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-70af-9b4b-d8719e7af60c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019eb2c2-a4c8-7c1e-8b92-0dbd62df5956" xlink:to="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-70af-9b4b-d8719e7af60c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019eb2c2-a4c8-7010-b09e-6f3f7d827ee8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-70af-9b4b-d8719e7af60c" xlink:to="loc_us-gaap_CommonClassAMember_019eb2c2-a4c8-7010-b09e-6f3f7d827ee8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019eb2c2-a4c8-76b3-9a43-995f0838df41" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019eb2c2-a4c8-70af-9b4b-d8719e7af60c" xlink:to="loc_us-gaap_CommonClassBMember_019eb2c2-a4c8-76b3-9a43-995f0838df41" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_019eb2c2-a4c8-7094-a0c6-a6d282e49399" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019eb2c2-a4c8-7ec2-b50a-c8f5de4f0858" xlink:to="loc_srt_ShareRepurchaseProgramAxis_019eb2c2-a4c8-7094-a0c6-a6d282e49399" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019eb2c2-a4c8-7094-a0c6-a6d282e49399_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019eb2c2-a4c8-7094-a0c6-a6d282e49399" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019eb2c2-a4c8-7094-a0c6-a6d282e49399_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019eb2c2-a4c8-771e-a27d-0ffd225ec562" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019eb2c2-a4c8-7094-a0c6-a6d282e49399" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019eb2c2-a4c8-771e-a27d-0ffd225ec562" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_RepurchaseProgram2026Member_019eb2c2-a4c8-707c-8c8e-25b34a929bce" xlink:href="sndr-20260630.xsd#sndr_RepurchaseProgram2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019eb2c2-a4c8-771e-a27d-0ffd225ec562" xlink:to="loc_sndr_RepurchaseProgram2026Member_019eb2c2-a4c8-707c-8c8e-25b34a929bce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsAxis_019eb2c2-a4c8-7b29-b7a8-93fdf31bba81" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019eb2c2-a4c8-7ec2-b50a-c8f5de4f0858" xlink:to="loc_us-gaap_DividendsAxis_019eb2c2-a4c8-7b29-b7a8-93fdf31bba81" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDomain_019eb2c2-a4c8-7b29-b7a8-93fdf31bba81_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DividendsAxis_019eb2c2-a4c8-7b29-b7a8-93fdf31bba81" xlink:to="loc_us-gaap_DividendsDomain_019eb2c2-a4c8-7b29-b7a8-93fdf31bba81_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDomain_019eb2c2-a4c8-740e-bb26-e75492e41bef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DividendsAxis_019eb2c2-a4c8-7b29-b7a8-93fdf31bba81" xlink:to="loc_us-gaap_DividendsDomain_019eb2c2-a4c8-740e-bb26-e75492e41bef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_O2026Q3DividendsMember_019eb2c2-a4c8-73bc-bf30-3cf530236af3" xlink:href="sndr-20260630.xsd#sndr_O2026Q3DividendsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_019eb2c2-a4c8-740e-bb26-e75492e41bef" xlink:to="loc_sndr_O2026Q3DividendsMember_019eb2c2-a4c8-73bc-bf30-3cf530236af3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019eb2c2-a4c8-7607-ac82-b623b447ce8e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019eb2c2-a4c8-7ec2-b50a-c8f5de4f0858" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019eb2c2-a4c8-7607-ac82-b623b447ce8e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019eb2c2-a4c8-7607-ac82-b623b447ce8e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019eb2c2-a4c8-7607-ac82-b623b447ce8e" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019eb2c2-a4c8-7607-ac82-b623b447ce8e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019eb2c2-a4c8-75fb-8b15-2a40aa881561" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019eb2c2-a4c8-7607-ac82-b623b447ce8e" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019eb2c2-a4c8-75fb-8b15-2a40aa881561" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019eb2c2-a4c8-72b4-a9ce-3dd1da62434a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019eb2c2-a4c8-75fb-8b15-2a40aa881561" xlink:to="loc_us-gaap_SubsequentEventMember_019eb2c2-a4c8-72b4-a9ce-3dd1da62434a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019eb2c2-a4c8-7dc7-acc0-e7e0652f20c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-72fe-bc0f-27803709c8dc" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019eb2c2-a4c8-7dc7-acc0-e7e0652f20c1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019eb2c2-a4c8-75e0-88cb-5c9b707369c8" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-72fe-bc0f-27803709c8dc" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019eb2c2-a4c8-75e0-88cb-5c9b707369c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValue_019eb2c2-a4c8-7c5d-bd0a-e2e2ad2d0480" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-72fe-bc0f-27803709c8dc" xlink:to="loc_us-gaap_TreasuryStockValue_019eb2c2-a4c8-7c5d-bd0a-e2e2ad2d0480" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019eb2c2-a4c8-7a3b-b75f-3adb6a72e511" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019eb2c2-a4c8-72fe-bc0f-27803709c8dc" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019eb2c2-a4c8-7a3b-b75f-3adb6a72e511" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/SharebasedCompensationGrantsDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#SharebasedCompensationGrantsDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/SharebasedCompensationGrantsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019eb2c2-a4c8-7571-97cf-d8f8fc3e2c09" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019eb2c2-a4c8-76cb-ba59-6f27d05ca8af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019eb2c2-a4c8-7571-97cf-d8f8fc3e2c09" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019eb2c2-a4c8-76cb-ba59-6f27d05ca8af" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019eb2c2-a4c8-7145-90a2-875b87317c53" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019eb2c2-a4c8-76cb-ba59-6f27d05ca8af" xlink:to="loc_us-gaap_PlanNameAxis_019eb2c2-a4c8-7145-90a2-875b87317c53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019eb2c2-a4c8-7145-90a2-875b87317c53_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019eb2c2-a4c8-7145-90a2-875b87317c53" xlink:to="loc_us-gaap_PlanNameDomain_019eb2c2-a4c8-7145-90a2-875b87317c53_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019eb2c2-a4c8-79d7-a377-788f62c9e732" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019eb2c2-a4c8-7145-90a2-875b87317c53" xlink:to="loc_us-gaap_PlanNameDomain_019eb2c2-a4c8-79d7-a377-788f62c9e732" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_A2017OmnibusIncentivePlanMember_019eb2c2-a4c8-7140-a61a-fbc881df0664" xlink:href="sndr-20260630.xsd#sndr_A2017OmnibusIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019eb2c2-a4c8-79d7-a377-788f62c9e732" xlink:to="loc_sndr_A2017OmnibusIncentivePlanMember_019eb2c2-a4c8-7140-a61a-fbc881df0664" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019eb2c2-a4c8-73a3-9223-bd03369f3111" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019eb2c2-a4c8-76cb-ba59-6f27d05ca8af" xlink:to="loc_us-gaap_AwardTypeAxis_019eb2c2-a4c8-73a3-9223-bd03369f3111" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019eb2c2-a4c8-73a3-9223-bd03369f3111_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019eb2c2-a4c8-73a3-9223-bd03369f3111" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019eb2c2-a4c8-73a3-9223-bd03369f3111_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019eb2c2-a4c8-7c80-8864-cc076050670a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019eb2c2-a4c8-73a3-9223-bd03369f3111" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019eb2c2-a4c8-7c80-8864-cc076050670a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_A2017OmnibusIncentivePlanMember_019eb2c2-a4c8-7580-805b-1c6f2dbb7122" xlink:href="sndr-20260630.xsd#sndr_A2017OmnibusIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019eb2c2-a4c8-7c80-8864-cc076050670a" xlink:to="loc_sndr_A2017OmnibusIncentivePlanMember_019eb2c2-a4c8-7580-805b-1c6f2dbb7122" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardDateAxis_019eb2c2-a4c8-7f20-905c-d4bacc9c9d89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019eb2c2-a4c8-76cb-ba59-6f27d05ca8af" xlink:to="loc_us-gaap_AwardDateAxis_019eb2c2-a4c8-7f20-905c-d4bacc9c9d89" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardDateDomain_019eb2c2-a4c8-7f20-905c-d4bacc9c9d89_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardDateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardDateAxis_019eb2c2-a4c8-7f20-905c-d4bacc9c9d89" xlink:to="loc_us-gaap_AwardDateDomain_019eb2c2-a4c8-7f20-905c-d4bacc9c9d89_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardDateDomain_019eb2c2-a4c8-782f-8c33-782492aea6ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardDateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardDateAxis_019eb2c2-a4c8-7f20-905c-d4bacc9c9d89" xlink:to="loc_us-gaap_AwardDateDomain_019eb2c2-a4c8-782f-8c33-782492aea6ea" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/SharebasedCompensationAdditionalInformationDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#SharebasedCompensationAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/SharebasedCompensationAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019eb2c2-a4c8-7c2a-b05f-034bbcf6131d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019eb2c2-a4c8-7e71-b594-653aae8c523e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019eb2c2-a4c8-7c2a-b05f-034bbcf6131d" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019eb2c2-a4c8-7e71-b594-653aae8c523e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019eb2c2-a4c8-7dd0-8f0e-91011375ccfe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019eb2c2-a4c8-7e71-b594-653aae8c523e" xlink:to="loc_us-gaap_PlanNameAxis_019eb2c2-a4c8-7dd0-8f0e-91011375ccfe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019eb2c2-a4c8-7dd0-8f0e-91011375ccfe_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019eb2c2-a4c8-7dd0-8f0e-91011375ccfe" xlink:to="loc_us-gaap_PlanNameDomain_019eb2c2-a4c8-7dd0-8f0e-91011375ccfe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019eb2c2-a4c8-73ca-8b3b-05c0cfc9d6ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019eb2c2-a4c8-7dd0-8f0e-91011375ccfe" xlink:to="loc_us-gaap_PlanNameDomain_019eb2c2-a4c8-73ca-8b3b-05c0cfc9d6ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_A2017OmnibusIncentivePlanMember_019eb2c2-a4c8-7563-a4e0-3e6fdff4b0fd" xlink:href="sndr-20260630.xsd#sndr_A2017OmnibusIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019eb2c2-a4c8-73ca-8b3b-05c0cfc9d6ca" xlink:to="loc_sndr_A2017OmnibusIncentivePlanMember_019eb2c2-a4c8-7563-a4e0-3e6fdff4b0fd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019eb2c2-a4c8-77bb-ab90-0f8556949e98" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019eb2c2-a4c8-7c2a-b05f-034bbcf6131d" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019eb2c2-a4c8-77bb-ab90-0f8556949e98" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019eb2c2-a4c8-7c31-a03e-9aa6baca717f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019eb2c2-a4c8-7c2a-b05f-034bbcf6131d" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019eb2c2-a4c8-7c31-a03e-9aa6baca717f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019eb2c2-a4c8-78cb-b140-3b7fef02c0cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019eb2c2-a4c8-7c2a-b05f-034bbcf6131d" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019eb2c2-a4c8-78cb-b140-3b7fef02c0cc" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/SegmentReportingAdditionalInformationDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#SegmentReportingAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/SegmentReportingAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a4c8-7883-a36a-cf6e60fd9aec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7dde-98d4-82b7c523484c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a4c8-7883-a36a-cf6e60fd9aec" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7dde-98d4-82b7c523484c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-7ef0-a379-cb3fab535f1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7dde-98d4-82b7c523484c" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-7ef0-a379-cb3fab535f1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7ef0-a379-cb3fab535f1e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-7ef0-a379-cb3fab535f1e" xlink:to="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-7ef0-a379-cb3fab535f1e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-795b-af06-eb0ef5ae1458" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a4c8-7ef0-a379-cb3fab535f1e" xlink:to="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-795b-af06-eb0ef5ae1458" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_TruckloadMember_019eb2c2-a4c8-7e52-9d9c-1dcbf88a0099" xlink:href="sndr-20260630.xsd#sndr_TruckloadMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-795b-af06-eb0ef5ae1458" xlink:to="loc_sndr_TruckloadMember_019eb2c2-a4c8-7e52-9d9c-1dcbf88a0099" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_LogisticsMember_019eb2c2-a4c8-7a2f-a2b1-2812872363a7" xlink:href="sndr-20260630.xsd#sndr_LogisticsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-795b-af06-eb0ef5ae1458" xlink:to="loc_sndr_LogisticsMember_019eb2c2-a4c8-7a2f-a2b1-2812872363a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateAndOtherMember_019eb2c2-a4c8-7e04-9661-4b54654b89f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019eb2c2-a4c8-795b-af06-eb0ef5ae1458" xlink:to="loc_us-gaap_CorporateAndOtherMember_019eb2c2-a4c8-7e04-9661-4b54654b89f3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsAxis_019eb2c2-a4c8-7f51-82ab-f5ae2c111c70" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7dde-98d4-82b7c523484c" xlink:to="loc_us-gaap_SubsegmentsAxis_019eb2c2-a4c8-7f51-82ab-f5ae2c111c70" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_019eb2c2-a4c8-7f51-82ab-f5ae2c111c70_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_019eb2c2-a4c8-7f51-82ab-f5ae2c111c70" xlink:to="loc_us-gaap_SubsegmentsDomain_019eb2c2-a4c8-7f51-82ab-f5ae2c111c70_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_019eb2c2-a4c8-7b45-9312-60e708c91932" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_019eb2c2-a4c8-7f51-82ab-f5ae2c111c70" xlink:to="loc_us-gaap_SubsegmentsDomain_019eb2c2-a4c8-7b45-9312-60e708c91932" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_OtherInsuranceMember_019eb2c2-a4c8-7065-acb4-a249b296e75f" xlink:href="sndr-20260630.xsd#sndr_OtherInsuranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_019eb2c2-a4c8-7b45-9312-60e708c91932" xlink:to="loc_sndr_OtherInsuranceMember_019eb2c2-a4c8-7065-acb4-a249b296e75f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_019eb2c2-a4c8-7c48-a25a-fe2041c089cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a4c8-7883-a36a-cf6e60fd9aec" xlink:to="loc_us-gaap_NumberOfReportableSegments_019eb2c2-a4c8-7c48-a25a-fe2041c089cc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019eb2c2-a4c8-7729-bc48-87f983b693fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a4c8-7883-a36a-cf6e60fd9aec" xlink:to="loc_us-gaap_Revenues_019eb2c2-a4c8-7729-bc48-87f983b693fc" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://schneider.com/role/SegmentReportingRevenuesandExpensesDetails" xlink:type="simple" xlink:href="sndr-20260630.xsd#SegmentReportingRevenuesandExpensesDetails"/>
  <link:definitionLink xlink:role="http://schneider.com/role/SegmentReportingRevenuesandExpensesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7acb-9c0d-be20cc1c209b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7acb-9c0d-be20cc1c209b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019eb2c2-a4c8-71f6-b59e-3cd908c915b2" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7acb-9c0d-be20cc1c209b" xlink:to="loc_srt_ConsolidationItemsAxis_019eb2c2-a4c8-71f6-b59e-3cd908c915b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019eb2c2-a4c8-71f6-b59e-3cd908c915b2_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019eb2c2-a4c8-71f6-b59e-3cd908c915b2" xlink:to="loc_srt_ConsolidationItemsDomain_019eb2c2-a4c8-71f6-b59e-3cd908c915b2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019eb2c2-a58c-7c83-9a24-a4f45dc3d99a" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019eb2c2-a4c8-71f6-b59e-3cd908c915b2" xlink:to="loc_srt_ConsolidationItemsDomain_019eb2c2-a58c-7c83-9a24-a4f45dc3d99a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019eb2c2-a58c-7641-bf72-e40fdbfbdac1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019eb2c2-a58c-7c83-9a24-a4f45dc3d99a" xlink:to="loc_us-gaap_OperatingSegmentsMember_019eb2c2-a58c-7641-bf72-e40fdbfbdac1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019eb2c2-a58c-753a-833c-9f5acd443a17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019eb2c2-a58c-7c83-9a24-a4f45dc3d99a" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019eb2c2-a58c-753a-833c-9f5acd443a17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_CorporateAndReconcilingItemsMember_019eb2c2-a58c-7dd9-a48a-6f690f4e940d" xlink:href="sndr-20260630.xsd#sndr_CorporateAndReconcilingItemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019eb2c2-a58c-7c83-9a24-a4f45dc3d99a" xlink:to="loc_sndr_CorporateAndReconcilingItemsMember_019eb2c2-a58c-7dd9-a48a-6f690f4e940d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a58c-7d66-a2fe-e126293d82b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7acb-9c0d-be20cc1c209b" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a58c-7d66-a2fe-e126293d82b5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019eb2c2-a58c-7d66-a2fe-e126293d82b5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a58c-7d66-a2fe-e126293d82b5" xlink:to="loc_us-gaap_SegmentDomain_019eb2c2-a58c-7d66-a2fe-e126293d82b5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019eb2c2-a58c-7b86-9418-574d5be19218" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019eb2c2-a58c-7d66-a2fe-e126293d82b5" xlink:to="loc_us-gaap_SegmentDomain_019eb2c2-a58c-7b86-9418-574d5be19218" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_TruckloadMember_019eb2c2-a58c-7338-97bc-072278ebf3da" xlink:href="sndr-20260630.xsd#sndr_TruckloadMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019eb2c2-a58c-7b86-9418-574d5be19218" xlink:to="loc_sndr_TruckloadMember_019eb2c2-a58c-7338-97bc-072278ebf3da" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_IntermodalMember_019eb2c2-a58c-73df-bfca-71eb839f7ada" xlink:href="sndr-20260630.xsd#sndr_IntermodalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019eb2c2-a58c-7b86-9418-574d5be19218" xlink:to="loc_sndr_IntermodalMember_019eb2c2-a58c-73df-bfca-71eb839f7ada" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_LogisticsMember_019eb2c2-a58c-7ca6-aef4-1d7c96c09e60" xlink:href="sndr-20260630.xsd#sndr_LogisticsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019eb2c2-a58c-7b86-9418-574d5be19218" xlink:to="loc_sndr_LogisticsMember_019eb2c2-a58c-7ca6-aef4-1d7c96c09e60" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsAxis_019eb2c2-a58c-769a-a606-8c73635f77c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7acb-9c0d-be20cc1c209b" xlink:to="loc_us-gaap_SubsegmentsAxis_019eb2c2-a58c-769a-a606-8c73635f77c8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_019eb2c2-a58c-769a-a606-8c73635f77c8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_019eb2c2-a58c-769a-a606-8c73635f77c8" xlink:to="loc_us-gaap_SubsegmentsDomain_019eb2c2-a58c-769a-a606-8c73635f77c8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_019eb2c2-a58c-7e89-9934-c760ac269205" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_019eb2c2-a58c-769a-a606-8c73635f77c8" xlink:to="loc_us-gaap_SubsegmentsDomain_019eb2c2-a58c-7e89-9934-c760ac269205" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsConsolidationItemsAxis_019eb2c2-a58c-7fcb-896b-658895062b6e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7acb-9c0d-be20cc1c209b" xlink:to="loc_us-gaap_SubsegmentsConsolidationItemsAxis_019eb2c2-a58c-7fcb-896b-658895062b6e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsConsolidationItemsDomain_019eb2c2-a58c-7fcb-896b-658895062b6e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsConsolidationItemsAxis_019eb2c2-a58c-7fcb-896b-658895062b6e" xlink:to="loc_us-gaap_SubsegmentsConsolidationItemsDomain_019eb2c2-a58c-7fcb-896b-658895062b6e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsConsolidationItemsDomain_019eb2c2-a58c-7698-a2fe-2df6fb2758b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsConsolidationItemsAxis_019eb2c2-a58c-7fcb-896b-658895062b6e" xlink:to="loc_us-gaap_SubsegmentsConsolidationItemsDomain_019eb2c2-a58c-7698-a2fe-2df6fb2758b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingReportedAsIfOldSegmentationBasisAxis_019eb2c2-a58c-7a7d-9e2a-aeb82473a8a9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingReportedAsIfOldSegmentationBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7acb-9c0d-be20cc1c209b" xlink:to="loc_us-gaap_SegmentReportingReportedAsIfOldSegmentationBasisAxis_019eb2c2-a58c-7a7d-9e2a-aeb82473a8a9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingReportedAsIfOldSegmentationBasisDomain_019eb2c2-a58c-7a7d-9e2a-aeb82473a8a9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingReportedAsIfOldSegmentationBasisDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SegmentReportingReportedAsIfOldSegmentationBasisAxis_019eb2c2-a58c-7a7d-9e2a-aeb82473a8a9" xlink:to="loc_us-gaap_SegmentReportingReportedAsIfOldSegmentationBasisDomain_019eb2c2-a58c-7a7d-9e2a-aeb82473a8a9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingReportedAsIfOldSegmentationBasisDomain_019eb2c2-a58c-731b-a7ae-05ed126926ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingReportedAsIfOldSegmentationBasisDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SegmentReportingReportedAsIfOldSegmentationBasisAxis_019eb2c2-a58c-7a7d-9e2a-aeb82473a8a9" xlink:to="loc_us-gaap_SegmentReportingReportedAsIfOldSegmentationBasisDomain_019eb2c2-a58c-731b-a7ae-05ed126926ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementAxis_019eb2c2-a58c-7d04-86f4-cead858ed2d3" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7acb-9c0d-be20cc1c209b" xlink:to="loc_srt_RestatementAxis_019eb2c2-a58c-7d04-86f4-cead858ed2d3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_019eb2c2-a58c-7d04-86f4-cead858ed2d3_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RestatementAxis_019eb2c2-a58c-7d04-86f4-cead858ed2d3" xlink:to="loc_srt_RestatementDomain_019eb2c2-a58c-7d04-86f4-cead858ed2d3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_019eb2c2-a58c-7025-b6fb-2a82969103cc" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RestatementAxis_019eb2c2-a58c-7d04-86f4-cead858ed2d3" xlink:to="loc_srt_RestatementDomain_019eb2c2-a58c-7025-b6fb-2a82969103cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportingUnitAxis_019fa923-5d4c-762e-9539-2832815d299a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReportingUnitAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019eb2c2-a4c8-7acb-9c0d-be20cc1c209b" xlink:to="loc_us-gaap_ReportingUnitAxis_019fa923-5d4c-762e-9539-2832815d299a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportingUnitDomain_019fa923-5d4c-762e-9539-2832815d299a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReportingUnitDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReportingUnitAxis_019fa923-5d4c-762e-9539-2832815d299a" xlink:to="loc_us-gaap_ReportingUnitDomain_019fa923-5d4c-762e-9539-2832815d299a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportingUnitDomain_019fa923-5d4c-706c-836d-8b069d1447f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReportingUnitDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReportingUnitAxis_019fa923-5d4c-762e-9539-2832815d299a" xlink:to="loc_us-gaap_ReportingUnitDomain_019fa923-5d4c-706c-836d-8b069d1447f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_Revenuesexcludingfuelsurcharge_019eb2c2-a58c-7650-8f92-aa0c393bdb98" xlink:href="sndr-20260630.xsd#sndr_Revenuesexcludingfuelsurcharge"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_sndr_Revenuesexcludingfuelsurcharge_019eb2c2-a58c-7650-8f92-aa0c393bdb98" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_FuelSurchargeRevenue_019eb2c2-a58c-728b-9a9f-339f426fc3e2" xlink:href="sndr-20260630.xsd#sndr_FuelSurchargeRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_sndr_FuelSurchargeRevenue_019eb2c2-a58c-728b-9a9f-339f426fc3e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019eb2c2-a58c-7782-8337-d58e9ec439b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_us-gaap_Revenues_019eb2c2-a58c-7782-8337-d58e9ec439b3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIncome_019eb2c2-a58c-770a-b2a5-38ff37108901" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_us-gaap_OtherIncome_019eb2c2-a58c-770a-b2a5-38ff37108901" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold_019eb2c2-a58c-7fbc-950b-6c8a7342a7a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold_019eb2c2-a58c-7fbc-950b-6c8a7342a7a8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_sndr_PurchasedTransportationFuelAndFuelTaxes_019eb2c2-a58c-7903-94a1-a502e8173aa9" xlink:href="sndr-20260630.xsd#sndr_PurchasedTransportationFuelAndFuelTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_sndr_PurchasedTransportationFuelAndFuelTaxes_019eb2c2-a58c-7903-94a1-a502e8173aa9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019eb2c2-a58c-70a7-ba08-8503398986de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019eb2c2-a58c-70a7-ba08-8503398986de" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingCostsAndExpenses_019eb2c2-a58c-798b-a559-6798be9875ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingCostsAndExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_us-gaap_OperatingCostsAndExpenses_019eb2c2-a58c-798b-a559-6798be9875ee" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_019eb2c2-a58c-7cd2-85f1-f46b19971291" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_019eb2c2-a58c-7cd2-85f1-f46b19971291" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019eb2c2-a58c-71d6-b2f4-0125e61539d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_us-gaap_OperatingIncomeLoss_019eb2c2-a58c-71d6-b2f4-0125e61539d2" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019eb2c2-a58c-7416-8809-6132222087d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019eb2c2-a58c-7416-8809-6132222087d6" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019eb2c2-a58c-7cfd-a9a8-fb3193ec818a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019eb2c2-a58c-7337-a1f4-ee5a443af69b" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019eb2c2-a58c-7cfd-a9a8-fb3193ec818a" xlink:type="arc" order="11"/>
  </link:definitionLink>
</link:linkbase>
