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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-12-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001859392</issuerCik>
        <issuerName>Galaxy Digital Inc.</issuerName>
        <issuerTradingSymbol>GLXY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002052994</rptOwnerCik>
            <rptOwnerName>Paquette Anthony</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GALAXY DIGITAL INC.</rptOwnerStreet1>
            <rptOwnerStreet2>300 VESEY STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10282</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>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-12-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>41720</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>24.43</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>333280</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents 41,720 shares of Class A common stock withheld for taxes upon the vesting of 93,750  RSUs on December 26, 2025.</footnote>
        <footnote id="F2">Includes 281,250 shares of Class A Common Stock to be delivered in settlement of a restricted share unit (&quot;RSU&quot;) award where 93,750 RSUs are scheduled to vest on December 26, 2026, 93,750 RSUs are scheduled to vest on December 26, 2027 and 93,750 RSUs are scheduled to vest on December 26, 2028.</footnote>
    </footnotes>

    <remarks>Exhibits - Exhibit 24 - Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Frances Fuqua, Attorney-in-Fact for Anthony Paquette</signatureName>
        <signatureDate>2025-12-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
