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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-04-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001414321</rptOwnerCik>
            <rptOwnerName>Schaefer John V.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SPORTSMAN'S WAREHOUSE</rptOwnerStreet1>
            <rptOwnerStreet2>7035 HIGH TECH DRIVE</rptOwnerStreet2>
            <rptOwnerCity>MIDVALE</rptOwnerCity>
            <rptOwnerState>UT</rptOwnerState>
            <rptOwnerZipCode>84047</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-04-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>58800</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1346089.984</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Includes 78,400 shares of restricted stock, which are scheduled to vest as to one-third of the shares awarded on each of the first, second and third anniversaries of the April 16, 2016 grant date, subject to the Reporting Person's continued employment.</footnote>
        <footnote id="F2">Includes 214,167 restricted stock units which are scheduled to vest on April 16, 2017, subject to the Reporting Person's continued employment or service.</footnote>
        <footnote id="F3">Represents a forfeiture of 58,500, or 50% of the maximum 117,600, performance-based restricted stock awards previously granted to the Reporting Person on April 16, 2016. The Reporting Person previously reported the grant of the maximum number of 117,600 shares of restricted stock that were subject to performance-based vesting requirements determined with respect to the Issuer's performance during fiscal year 2016. On April 4, 2017, the Compensation Committee of the Board of Directors of the Issuer determined that the number of shares eligible to vest for such restricted stock award, based on actual performance of the Issuer, was 50% of the maximum number of shares previously reported. Of the remaining 58,500 shares eligible to vest based on performance, 19,500 shares will vest on April 16, 2017 and 19,500 shares will vest, subject to the Reporting Persons continued employment, on each of April 16, 2018 and April 16, 2019.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>John V. Shaefer</signatureName>
        <signatureDate>2017-04-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
