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

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-10-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001541401</issuerCik>
        <issuerName>Empire State Realty Trust, Inc.</issuerName>
        <issuerTradingSymbol>ESRT</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001076484</rptOwnerCik>
            <rptOwnerName>MALKIN ANTHONY E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>C/O EMPIRE STATE REALTY TRUST, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>111 WEST 33RD STREET, 12TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10120</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2026-10-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3061902</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3061902</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>60368</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By spouse and family trusts and entities controlled by the Reporting Person.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>LTIP Units</value>
                <footnoteId id="F3"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2026-10-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3061902</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3061902</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4499189</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">A total of 3,061,902 of vested LTIP Units were converted by the Reporting Person on a one-for-one basis into Operating Partnership Units, which were then redeemed for an equal number of shares of the Issuer's Class A Common Stock. See Note 3 below for a description of the conversion and exchange rights of the LTIP Units and Operating Partnership Units. All capitalized terms used herein are defined in Note 3 below.</footnote>
        <footnote id="F2">Includes Class A Common Stock held by (i) the Reporting Person's spouse and (ii) family trusts and entities for which the Reporting Person has sole voting and investment power as sole manager or sole trustee, as applicable, or the Reporting Person and his spouse have shared voting and investment power as managers or trustees, as applicable, all for the benefit of the Reporting Person, his spouse, and certain other members of their extended family. The Reporting Person disclaims beneficial ownership of such Class A Common Stock except to the extent of his pecuniary interest therein.</footnote>
        <footnote id="F3">Represents long term incentive plan units (&quot;LTIP Units&quot;), a class of units of Empire State Realty OP, L.P. (the &quot;Operating Partnership&quot;) in which Empire State Realty Trust, Inc. (the &quot;Issuer&quot;) is the sole general partner. Conditioned upon minimum allocations to the capital accounts of the LTIP Units for federal income tax purposes, vested LTIP Units are convertible by the Reporting Person, upon vesting, into an equivalent number of units of limited partnership interest (&quot;Operating Partnership Units&quot;) of the Operating Partnership, which are redeemable by the holder for shares of Class A common stock, par value $0.01 (&quot;Class A Common Stock&quot;) of the Issuer on a one-for-one basis or the cash value of such shares, at the Issuer's option. The rights to convert LTIP Units into Operating Partnership Units and redeem Operating Partnership Units do not have expiration dates.</footnote>
        <footnote id="F4">These LTIP Units are fully vested.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Susanne J. Lieu, Attorney-in-Fact</signatureName>
        <signatureDate>2026-10-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
