<?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>0001830519</rptOwnerCik>
            <rptOwnerName>FORLENZA JOSEPH M</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; CRO</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>4715</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24763</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4496</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1220</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>524</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Common Stock Right to Buy</value>
                <footnoteId id="F5"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>31.15</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <value>2028-04-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>12635</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12635</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">Represents an unvested time-based restricted stock award granted on 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="F3">Represents an unvested time-based restricted stock award granted on April 1, 2022, which shall vest over 3 years in on-third increments, beginning 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, 2021, which shall vest over 3 years in one-third increments, beginning April 1, 2022, and on each anniversary thereafter, subject to continued employment.</footnote>
        <footnote id="F5">Granted pursuant to the Company's Amended and Restated 2013 Incentive Plan.</footnote>
        <footnote id="F6">Represents stock option granted on April 2, 2018 (&quot;grant date&quot;) that vests over 3 years in one-third increments each anniversary of the date of grantbeginning on the first anniversary of the date of grant, subject to continued employment.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Kathy L. Hsu as Power of Attorney for Joseph M. Forlenza</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
0001830519
FORLENZA JOSEPH M
P.O. BOX 9012
STUART
FL
34995
0
1
0
0
EVP & CRO
0
Common Stock
2024-02-29
4
A
0
4715
0
A
24763
D
Common Stock
4496
D
Common Stock
1220
D
Common Stock
524
D
Common Stock Right to Buy
31.15
2028-04-02
Common Stock
12635
12635
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.
Represents an unvested time-based restricted stock award granted on 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, 2022, which shall vest over 3 years in on-third increments, beginning April 1, 2023, and on each anniversary thereafter, subject to continued employment.
Represents an unvested time-based restricted stock award granted April 1, 2021, which shall vest over 3 years in one-third increments, beginning April 1, 2022, and on each anniversary thereafter, subject to continued employment.
Granted pursuant to the Company's Amended and Restated 2013 Incentive Plan.
Represents stock option granted on April 2, 2018 ("grant date") that vests over 3 years in one-third increments each anniversary of the date of grantbeginning on the first anniversary of the date of grant, subject to continued employment.
/s/ Kathy L. Hsu as Power of Attorney for Joseph M. Forlenza
2024-03-04