    <SEC-DOCUMENT>0001387131-21-006893-index.html : 20210625
    <SEC-HEADER>0001387131-21-006893.hdr.sgml : 20210625
    <ACCEPTANCE-DATETIME>20210625165408
    ACCESSION NUMBER:		0001387131-21-006893
    CONFORMED SUBMISSION TYPE:	N-CSRS
    PUBLIC DOCUMENT COUNT:		13
    CONFORMED PERIOD OF REPORT:	20210430
    FILED AS OF DATE:		20210625
    DATE AS OF CHANGE:		20210625
    EFFECTIVENESS DATE:		20210625

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			CALAMOS STRATEGIC TOTAL RETURN FUND
    		CENTRAL INDEX KEY:			0001275214
    		IRS NUMBER:				043785941
    		FISCAL YEAR END:			1031

    	FILING VALUES:
    		FORM TYPE:		N-CSRS
    		SEC ACT:		1940 Act
    		SEC FILE NUMBER:	811-21484
    		FILM NUMBER:		211048739

    	BUSINESS ADDRESS:
    		STREET 1:		2020 CALAMOS COURT
    		STREET 2:		C/O CALAMOS ADVISORS LLC
    		CITY:			NAPERVILLE
    		STATE:			IL
    		ZIP:			60653
    		BUSINESS PHONE:		6302451046

    	MAIL ADDRESS:
    		STREET 1:		2020 CALAMOS COURT
    		STREET 2:		C/O CALAMOS ADVISORS LLC
    		CITY:			NAPERVILLE
    		STATE:			IL
    		ZIP:			60653
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>N-CSRS
    <SEQUENCE>1
    <FILENAME>csq-ncsrs_043021.htm
    <DESCRIPTION>CERTIFIED SEMI-ANNUAL SHAREHOLDER REPORT
    <TEXT>
    Document 1 - file: csq-ncsrs_043021.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.CERT
    <SEQUENCE>2
    <FILENAME>ex99-cert.htm
    <DESCRIPTION>CERTIFICATIONS
    <TEXT>
    Document 2 - file: ex99-cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.906 CERT
    <SEQUENCE>3
    <FILENAME>ex99-906cert.htm
    <DESCRIPTION>SECTION 906 CERTIFICATION
    <TEXT>
    Document 3 - file: ex99-906cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>csq-ncsrs_043021img001.gif
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 4 - file: csq-ncsrs_043021img001.gif

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>csq-ncsrs_043021img002.gif
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 5 - file: csq-ncsrs_043021img002.gif

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>csq-ncsrs_043021img003.gif
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: csq-ncsrs_043021img003.gif

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>csq-ncsrs_043021img004.gif
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: csq-ncsrs_043021img004.gif

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>csq-ncsrs_043021img005.gif
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: csq-ncsrs_043021img005.gif

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>csq-ncsrs_043021img006.gif
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: csq-ncsrs_043021img006.gif

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>csq-ncsrs_043021img007.gif
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: csq-ncsrs_043021img007.gif

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>csq-ncsrs_043021img008.gif
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: csq-ncsrs_043021img008.gif

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>csq-ncsrs_043021img009.gif
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: csq-ncsrs_043021img009.gif

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>csq-ncsrs_043021img010.gif
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: csq-ncsrs_043021img010.gif

    </DOCUMENT>
    </SEC-DOCUMENT>