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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2019-09-25</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000712770</issuerCik>
        <issuerName>ONE LIBERTY PROPERTIES INC</issuerName>
        <issuerTradingSymbol>OLP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000812291</rptOwnerCik>
            <rptOwnerName>MIZUHO SECURITIES USA LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>320 PARK AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>12TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <remarks>No securities are beneficially owned.
On September 25 2019 the Reporting Person entered into master securities loan agreements with each lender party signatory thereto (collectively the MSLAs) pursuant to which the Reporting Person borrowed an aggregate total of [2,716,453] shares of common stock of the Issuer which caused the Reporting Person to become a greater than ten percent owner with respect to the Issuer.  On September 26 2019 the Reporting Person returned [2,716,453] shares of the Issuer pursuant to the MSLAs.  Following the return of the borrowed shares the Reporting Person was no longer a greater than ten percent owner with respect to the Issuer.  To the extent the Reporting Person is entitled to receive any dividends with respect to the previously borrowed shares of the Issuer such dividends will be subject to the terms and conditions of the MSLAs.  The Reporting Person disclaims beneficial ownership of the previously borrowed shares of the Issuer for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934 as amended.</remarks>

    <ownerSignature>
        <signatureName>Gregory Doig</signatureName>
        <signatureDate>2019-10-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
