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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-02-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000730708</issuerCik>
        <issuerName>SEACOAST BANKING CORP OF FLORIDA</issuerName>
        <issuerTradingSymbol>SBCF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001815460</rptOwnerCik>
            <rptOwnerName>DEXTER TRACEY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>P.O. BOX 9012</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>STUART</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>34995</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP &amp; CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-02-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5242</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18442</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>244.211</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1952</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4496</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>582</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F5"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>656</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F6"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Common Stock Right to Buy</value>
                <footnoteId id="F7"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>31.15</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F8"/>
            </exerciseDate>
            <expirationDate>
                <value>2028-04-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2842</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2842</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares subject to performance based restricted stock units (&quot;PSUs&quot;) granted on April 1, 2021, that were subject to performance requirements which were attained over a period ending December 31, 2023.  On February 29, 2024, the Company's Compensation and Governance Committee certified the number of shares attained based on the performance criteria, which will vest on December 31, 2024, provided the recipient remains in continuous service with the Company on the vesting  date.</footnote>
        <footnote id="F2">Held in Seacoasts Executive Deferred Compensation Plan.</footnote>
        <footnote id="F3">Represents an unvested time-based restricted stock award granted on April 1, 2022, which shall vest over 3 years in one-third increments, beginning on April 1, 2023, and on each anniversary thereafter, subject to continued employment.</footnote>
        <footnote id="F4">Represents an unvested time-based restricted stock award granted April 1, 2023, which shall vest over 3 years in one-third increments, beginning April 1, 2024, and on each anniversary thereafter, subject to continued employment.</footnote>
        <footnote id="F5">Represents an unvested time-based restricted stock award granted on April 1, 2021, which shall vest over 3 years in one-third increments , beginning on April 1, 2022, and on each anniversary thereafter, subject to continued employment.</footnote>
        <footnote id="F6">Shares in the Company's Employee Stock Purchase Plan.</footnote>
        <footnote id="F7">Granted pursuant to the Company's Amended and Restated 2013 Incentive Plan.</footnote>
        <footnote id="F8">Vests over 3 years in one-third increments each anniversary of the date of grant beginning on the first anniversary of the date of grant (the date indicated), subject to continued employment.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Kathy L. Hsu as Power of Attorney for Tracey Dexter</signatureName>
        <signatureDate>2024-03-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0508
4
2024-02-29
0
0000730708
SEACOAST BANKING CORP OF FLORIDA
SBCF
0001815460
DEXTER TRACEY
P.O. BOX 9012
STUART
FL
34995
0
1
0
0
EVP & CFO
0
Common Stock
2024-02-29
4
A
0
5242
0
A
18442
D
Common Stock
244.211
D
Common Stock
1952
D
Common Stock
4496
D
Common Stock
582
D
Common Stock
656
D
Common Stock Right to Buy
31.15
2028-04-02
Common Stock
2842
2842
D
Represents shares subject to performance based restricted stock units ("PSUs") granted on April 1, 2021, that were subject to performance requirements which were attained over a period ending December 31, 2023.  On February 29, 2024, the Company's Compensation and Governance Committee certified the number of shares attained based on the performance criteria, which will vest on December 31, 2024, provided the recipient remains in continuous service with the Company on the vesting  date.
Held in Seacoasts Executive Deferred Compensation Plan.
Represents an unvested time-based restricted stock award granted on April 1, 2022, which shall vest over 3 years in one-third increments, beginning on April 1, 2023, and on each anniversary thereafter, subject to continued employment.
Represents an unvested time-based restricted stock award granted April 1, 2023, which shall vest over 3 years in one-third increments, beginning April 1, 2024, and on each anniversary thereafter, subject to continued employment.
Represents an unvested time-based restricted stock award granted on April 1, 2021, which shall vest over 3 years in one-third increments , beginning on April 1, 2022, and on each anniversary thereafter, subject to continued employment.
Shares in the Company's Employee Stock Purchase Plan.
Granted pursuant to the Company's Amended and Restated 2013 Incentive Plan.
Vests over 3 years in one-third increments each anniversary of the date of grant beginning on the first anniversary of the date of grant (the date indicated), subject to continued employment.
/s/ Kathy L. Hsu as Power of Attorney for Tracey Dexter
2024-03-04