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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-07-10</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>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-07-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2662.407</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.59</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>246067.391</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </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 91,467 shares of restricted stock, which are scheduled to vest in substantially equal installments on April 16, 2018 and April 16, 2019 subject to the Reporting Person's continued employment.</footnote>
        <footnote id="F3">Includes 150,000 restricted stock units which are scheduled to vest, subject to the Reporting Person's continued employment, as to one-third of the shares awarded on April 16, 2018, April 16, 2019, and April 16, 2020. Each restricted stock unit represents the right to receive one share of the Issuer's common stock</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ John V. Schaefer</signatureName>
        <signatureDate>2017-07-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
