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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-07-07</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>2020-07-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1251.71</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.83</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>134372.60</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">These shares were acquired under the Sportsman's Warehouse Holdings, Inc. Employee Stock Purchase Plan.</footnote>
        <footnote id="F2">Includes 37,744 restricted stock units which are scheduled to vest in three substantially equal installments 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 represents the right to receive one share of the Issuer's common stock.</footnote>
        <footnote id="F3">Includes 19,102 restricted stock units are scheduled to vest in equal installments on 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="F4">Includes 64,239 restricted stock units which are scheduled to vest on April 16, 2022, subject to the Reporting Person's continued employment. Each restricted stock unit representsthe right to receive one share of the Issuer's common stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Robert Julian</signatureName>
        <signatureDate>2020-07-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
