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

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-04-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001884082</issuerCik>
        <issuerName>Polestar Automotive Holding UK PLC</issuerName>
        <issuerTradingSymbol>PSNY</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002116011</rptOwnerCik>
            <rptOwnerName>Henricsson Nina Josefin</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>true</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>ASSAR GABRIELSSONS VAG 9</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GOTHENBURG</rptOwnerCity>
            <rptOwnerNonUSStateTerritory></rptOwnerNonUSStateTerritory>
            <rptOwnerCountry>V7</rptOwnerCountry>
            <rptOwnerZipCode>SE-405 31</rptOwnerZipCode>
            <rptOwnerStateDescription>SWEDEN</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Human Resources Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A American Depositary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2026-04-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>152</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.6824</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>197</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">All of the Class A American Depositary Shares (&quot;ADSs&quot;) were sold pursuant to a sell to cover transaction to satisfy tax withholding obligations upon the vesting of equity awards. The sale was executed automatically pursuant to a sell to cover arrangement and does not represent a discretionary trade by the Reporting Person.</footnote>
        <footnote id="F2">The price reported is a weighted average price. These ADSs were sold as part of block trades by the broker executing the sell to cover transactions over several days for multiple security holders of the Issuer at weighted average prices ranging from $17.5813 to $17.7911, inclusive.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Chris Bailey-Gates, Attorney-in-fact</signatureName>
        <signatureDate>2026-04-29</signatureDate>
    </ownerSignature>
</ownershipDocument>