<SEC-DOCUMENT>0001193125-21-158557-index.html : 20210512
<SEC-HEADER>0001193125-21-158557.hdr.sgml : 20210512
<ACCEPTANCE-DATETIME>20210512105253
ACCESSION NUMBER:		0001193125-21-158557
CONFORMED SUBMISSION TYPE:	424B5
PUBLIC DOCUMENT COUNT:		3
FILED AS OF DATE:		20210512
DATE AS OF CHANGE:		20210512

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Arthur J. Gallagher & Co.
		CENTRAL INDEX KEY:			0000354190
		STANDARD INDUSTRIAL CLASSIFICATION:	INSURANCE AGENTS BROKERS & SERVICES [6411]
		IRS NUMBER:				362151613
		STATE OF INCORPORATION:			IL
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		424B5
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-254015
		FILM NUMBER:		21913967

	BUSINESS ADDRESS:	
		STREET 1:		2850 GOLF ROAD
		CITY:			ROLLING MEADOWS
		STATE:			IL
		ZIP:			60008-4050
		BUSINESS PHONE:		630-773-3800

	MAIL ADDRESS:	
		STREET 1:		2850 GOLF ROAD
		CITY:			ROLLING MEADOWS
		STATE:			IL
		ZIP:			60008-4050

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ARTHUR J. GALLAGHER & CO.
		DATE OF NAME CHANGE:	20190819

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GALLAGHER ARTHUR J & CO
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>424B5
<SEQUENCE>1
<FILENAME>d73127d424b5.htm
<DESCRIPTION>424B5
<TEXT>
Document 1 - file: d73127d424b5.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>g128383g99s21.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 2 - file: g128383g99s21.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>g73127g59j78.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: g73127g59j78.jpg

</DOCUMENT>
</SEC-DOCUMENT>