<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-03-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001132105</issuerCik>
        <issuerName>SPORTSMAN'S WAREHOUSE HOLDINGS, INC.</issuerName>
        <issuerTradingSymbol>SPWH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001559839</rptOwnerCik>
            <rptOwnerName>JULIAN ROBERT K.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1475 WEST 9000 SOUTH</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE A</rptOwnerStreet2>
            <rptOwnerCity>WEST JORDAN</rptOwnerCity>
            <rptOwnerState>UT</rptOwnerState>
            <rptOwnerZipCode>84088</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-03-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>37744</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>133120.89</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Reflects the grant of restricted stock units by the Issuer to the Reporting Person on March 24, 2020. The restricted stock units are scheduled to vest in three substantially equalinstallments on March 24, 2021, March 24, 2022, and March 24, 2023, subject to the Reporting Person's continued employment with the Issuer. Each restricted stock unit representsthe right to receive one share of the Issuer's common stock.</footnote>
        <footnote id="F2">Includes 28,653 restricted stock units which are scheduled to vest in three substantially equal installments on April 16, 2020, April 16, 2021, and April 16, 2022, subject to the Reporting Person's continued employment with the Issuer. Each restricted stock unit represents the right to receive one share of the Issuer's common stock.</footnote>
        <footnote id="F3">Includes 64,239 restricted stock units which are scheduled to vest on April 16, 2022, subject to the Reporting Person's continued employment with the Issuer. Each restricted stock unit represents the right to receive one share of the Issuer's common stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Robert Julian</signatureName>
        <signatureDate>2020-04-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
