    <SEC-DOCUMENT>0001213900-21-001131-index.html : 20210108
    <SEC-HEADER>0001213900-21-001131.hdr.sgml : 20210108
    <ACCEPTANCE-DATETIME>20210108140023
    ACCESSION NUMBER:		0001213900-21-001131
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		49
    CONFORMED PERIOD OF REPORT:	20210108
    ITEM INFORMATION:		Regulation FD Disclosure
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20210108
    DATE AS OF CHANGE:		20210108

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			ONE LIBERTY PROPERTIES INC
    		CENTRAL INDEX KEY:			0000712770
    		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
    		IRS NUMBER:				133147497
    		STATE OF INCORPORATION:			MD
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-09279
    		FILM NUMBER:		21516915

    	BUSINESS ADDRESS:
    		STREET 1:		60 CUTTER MILL RD
    		STREET 2:		SUITE 303
    		CITY:			GREAT NECK
    		STATE:			NY
    		ZIP:			11021-3190
    		BUSINESS PHONE:		5164663100

    	MAIL ADDRESS:
    		STREET 1:		60 CUTTER MILL ROAD
    		STREET 2:		SUITE 303
    		CITY:			GREAT NECK
    		STATE:			NY
    		ZIP:			11021-3190

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	ONE LIBERTY FIRESTONE PROPERTIES INC
    		DATE OF NAME CHANGE:	19851112
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>ea132976-8k_oneliberty.htm
    <DESCRIPTION>CURRENT REPORT
    <TEXT>
    Document 1 - file: ea132976-8k_oneliberty.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.1
    <SEQUENCE>2
    <FILENAME>ea132976ex99-1_oneliberty.htm
    <DESCRIPTION>PRESENTATION - JANUARY 2021
    <TEXT>
    Document 2 - file: ea132976ex99-1_oneliberty.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>3
    <FILENAME>olp-20210108.xsd
    <DESCRIPTION>XBRL SCHEMA FILE
    <TEXT>
    Document 3 - file: olp-20210108.xsd

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.LAB
    <SEQUENCE>4
    <FILENAME>olp-20210108_lab.xml
    <DESCRIPTION>XBRL LABEL FILE
    <TEXT>
    Document 4 - file: olp-20210108_lab.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.PRE
    <SEQUENCE>5
    <FILENAME>olp-20210108_pre.xml
    <DESCRIPTION>XBRL PRESENTATION FILE
    <TEXT>
    Document 5 - file: olp-20210108_pre.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>ex99-1_001.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: ex99-1_001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>ex99-1_002.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: ex99-1_002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>ex99-1_003.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: ex99-1_003.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>ex99-1_004.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: ex99-1_004.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>ex99-1_005.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: ex99-1_005.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>ex99-1_006.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: ex99-1_006.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>ex99-1_007.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: ex99-1_007.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>ex99-1_008.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: ex99-1_008.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>ex99-1_009.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: ex99-1_009.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>ex99-1_010.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: ex99-1_010.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>ex99-1_011.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 16 - file: ex99-1_011.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>17
    <FILENAME>ex99-1_012.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 17 - file: ex99-1_012.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>ex99-1_013.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 18 - file: ex99-1_013.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>ex99-1_014.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 19 - file: ex99-1_014.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>ex99-1_015.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 20 - file: ex99-1_015.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>21
    <FILENAME>ex99-1_016.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 21 - file: ex99-1_016.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>22
    <FILENAME>ex99-1_017.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 22 - file: ex99-1_017.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>23
    <FILENAME>ex99-1_018.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 23 - file: ex99-1_018.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>24
    <FILENAME>ex99-1_019.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 24 - file: ex99-1_019.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>25
    <FILENAME>ex99-1_020.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 25 - file: ex99-1_020.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>26
    <FILENAME>ex99-1_021.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 26 - file: ex99-1_021.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>27
    <FILENAME>ex99-1_022.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 27 - file: ex99-1_022.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>28
    <FILENAME>ex99-1_023.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 28 - file: ex99-1_023.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>29
    <FILENAME>ex99-1_024.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 29 - file: ex99-1_024.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>30
    <FILENAME>ex99-1_025.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 30 - file: ex99-1_025.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>31
    <FILENAME>ex99-1_026.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 31 - file: ex99-1_026.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>32
    <FILENAME>ex99-1_027.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 32 - file: ex99-1_027.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>33
    <FILENAME>ex99-1_028.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 33 - file: ex99-1_028.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>34
    <FILENAME>ex99-1_029.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 34 - file: ex99-1_029.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>35
    <FILENAME>ex99-1_030.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 35 - file: ex99-1_030.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>36
    <FILENAME>ex99-1_031.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 36 - file: ex99-1_031.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>37
    <FILENAME>ex99-1_032.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 37 - file: ex99-1_032.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>38
    <FILENAME>ex99-1_033.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 38 - file: ex99-1_033.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>39
    <FILENAME>ex99-1_034.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 39 - file: ex99-1_034.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>40
    <FILENAME>ex99-1_035.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 40 - file: ex99-1_035.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>41
    <FILENAME>ex99-1_036.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 41 - file: ex99-1_036.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>42
    <FILENAME>ea132976-8k_oneliberty_htm.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 42 - file: ea132976-8k_oneliberty_htm.html

    Document 42 - RAW XML: ea132976-8k_oneliberty_htm.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>43
    <FILENAME>R1.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 43 - file: R1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EXCEL
    <SEQUENCE>44
    <FILENAME>Financial_Report.xlsx
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 44 - file: Financial_Report.xlsx

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>45
    <FILENAME>Show.js
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 45 - file: Show.js

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>46
    <FILENAME>report.css
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 46 - file: report.css

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>47
    <FILENAME>FilingSummary.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 47 - file: FilingSummary.html

    Document 47 - RAW XML: FilingSummary.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>49
    <FILENAME>MetaLinks.json
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 49 - file: MetaLinks.json

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>ZIP
    <SEQUENCE>50
    <FILENAME>0001213900-21-001131-xbrl.zip
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 50 - file: 0001213900-21-001131-xbrl.zip

    </DOCUMENT>
    </SEC-DOCUMENT>