<SEC-DOCUMENT>0001672825-25-000003.txt : 20250626
<SEC-HEADER>0001672825-25-000003.hdr.sgml : 20250626
<ACCEPTANCE-DATETIME>20250626163916
ACCESSION NUMBER:		0001672825-25-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250624
FILED AS OF DATE:		20250626
DATE AS OF CHANGE:		20250626

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Mueller David J
		CENTRAL INDEX KEY:			0001672825
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-42584
		FILM NUMBER:		251080919

	MAIL ADDRESS:	
		STREET 1:		10 TERRACE ROAD
		CITY:			LADERA RANCH
		STATE:			CA
		ZIP:			92694

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SmartStop Self Storage REIT, Inc.
		CENTRAL INDEX KEY:			0001585389
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		ORGANIZATION NAME:           	05 Real Estate & Construction
		EIN:				461722812
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		10 TERRACE ROAD
		CITY:			LADERA RANCH
		STATE:			CA
		ZIP:			92694
		BUSINESS PHONE:		949 429 6600

	MAIL ADDRESS:	
		STREET 1:		10 TERRACE ROAD
		CITY:			LADERA RANCH
		STATE:			CA
		ZIP:			92694

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Strategic Storage Trust II, Inc.
		DATE OF NAME CHANGE:	20130828
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-06-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001585389</issuerCik>
        <issuerName>SmartStop Self Storage REIT, Inc.</issuerName>
        <issuerTradingSymbol>SMA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001672825</rptOwnerCik>
            <rptOwnerName>Mueller David J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>10 TERRACE ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LADERA RANCH</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92694</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7190.87</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Long-Term Incentive Plan Units</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-06-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2814</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2814</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7234.25</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeHolding>
            <securityTitle>
                <value>Long-Term Incentive Plan Units</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>9598</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9598</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents 7,190.87 shares of Class A Common Stock previously reported as being owned by the Reporting Person.</footnote>
        <footnote id="F2">Represents long-term incentive plan units (&quot;LTIP Units&quot;) of SmartStop OP, L.P., the Issuer's operating partnership (the &quot;Operating Partnership&quot;). Vested LTIP Units are convertible into Class A common units of the Operating Partnership (&quot;Class A Common Units&quot;). Class A Common Units are redeemable by the holder for, at the election of the Issuer, shares of the Issuer's Class A Common Stock on a one-for-one basis or the cash value of such shares.</footnote>
        <footnote id="F3">The Reporting Person was awarded 2,814 LTIP Units upon his reelection to the board of directors, which LTIP Units vest one year from such reelection.</footnote>
        <footnote id="F4">Represents 9,598 LTIP Units previously reported as being owned by the Reporting Person, which LTIP Units vest ratably over four years commencing on the first anniversary of the issuance thereof, subject to the Reporting Person's continued employment or service through each vesting date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ David J. Mueller</signatureName>
        <signatureDate>2025-06-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
