    <SEC-DOCUMENT>0000909108-20-000032-index.html : 20200313
    <SEC-HEADER>0000909108-20-000032.hdr.sgml : 20200313
    <ACCEPTANCE-DATETIME>20200313160415
    ACCESSION NUMBER:		0000909108-20-000032
    CONFORMED SUBMISSION TYPE:	DEF 14A
    PUBLIC DOCUMENT COUNT:		6
    CONFORMED PERIOD OF REPORT:	20200428
    FILED AS OF DATE:		20200313
    DATE AS OF CHANGE:		20200313
    EFFECTIVENESS DATE:		20200313

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			DIAMOND HILL INVESTMENT GROUP INC
    		CENTRAL INDEX KEY:			0000909108
    		STANDARD INDUSTRIAL CLASSIFICATION:	INVESTMENT ADVICE [6282]
    		IRS NUMBER:				650190407
    		STATE OF INCORPORATION:			OH
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		DEF 14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-24498
    		FILM NUMBER:		20712634

    	BUSINESS ADDRESS:
    		STREET 1:		325 JOHN H MCCONNELL BLVD
    		STREET 2:		SUITE 200
    		CITY:			COLUMBUS
    		STATE:			OH
    		ZIP:			43215
    		BUSINESS PHONE:		6142553333

    	MAIL ADDRESS:
    		STREET 1:		325 JOHN H MCCONNELL BLVD
    		STREET 2:		SUITE 200
    		CITY:			COLUMBUS
    		STATE:			OH
    		ZIP:			43215

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	BANC STOCK GROUP INC
    		DATE OF NAME CHANGE:	19971016

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	HEARTLAND GROUP OF COMPANIES INC
    		DATE OF NAME CHANGE:	19940301

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	HEARTLAND FINANCIAL GROUP INC
    		DATE OF NAME CHANGE:	19930714
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>DEF 14A
    <SEQUENCE>1
    <FILENAME>proxystatement-2020.htm
    <DESCRIPTION>DIAMOND HILL INVESTMENT GROUP - PROXY STATEMENT
    <TEXT>
    Document 1 - file: proxystatement-2020.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>2
    <FILENAME>proxycardfinalpage1.jpg
    <TEXT>
    Document 2 - file: proxycardfinalpage1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>proxycardfinalpage2.jpg
    <TEXT>
    Document 3 - file: proxycardfinalpage2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>esighba01.jpg
    <TEXT>
    Document 4 - file: esighba01.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>proxystatement2015image1a08.jpg
    <TEXT>
    Document 5 - file: proxystatement2015image1a08.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>garyyounga03.jpg
    <TEXT>
    Document 6 - file: garyyounga03.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>