<SEC-DOCUMENT>0001462217-21-000001.txt : 20210621
<SEC-HEADER>0001462217-21-000001.hdr.sgml : 20210621
<ACCEPTANCE-DATETIME>20210621202431
ACCESSION NUMBER:		0001462217-21-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210616
FILED AS OF DATE:		20210621
DATE AS OF CHANGE:		20210621

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Mathews Paula M.
		CENTRAL INDEX KEY:			0001462217

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-55617
		FILM NUMBER:		211032701

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

	FORMER NAME:	
		FORMER CONFORMED NAME:	Mathews Paula
		DATE OF NAME CHANGE:	20090417

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SmartStop Self Storage REIT, Inc.
		CENTRAL INDEX KEY:			0001585389
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				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>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-06-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001462217</rptOwnerCik>
            <rptOwnerName>Mathews Paula M.</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>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-06-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>27523.08</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held by Paula M. Mathews Living Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The Reporting Person was awarded 6,000.00 shares of restricted stock upon her reelection to the board of directors, which shares vest one year from such reelection.</footnote>
        <footnote id="F2">Includes shares previously reported as being directly owned by the Reporting Person that have since been transferred into a trust of which the Reporting Person is the sole beneficiary.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Paula M. Mathews</signatureName>
        <signatureDate>2021-06-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
