<SEC-DOCUMENT>0001959173-25-003408.txt : 20250521
<SEC-HEADER>0001959173-25-003408.hdr.sgml : 20250521
<ACCEPTANCE-DATETIME>20250521162430
ACCESSION NUMBER:		0001959173-25-003408
CONFORMED SUBMISSION TYPE:	144
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20250521
DATE AS OF CHANGE:		20250521

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Arthur J. Gallagher & Co.
		CENTRAL INDEX KEY:			0000354190
		STANDARD INDUSTRIAL CLASSIFICATION:	INSURANCE AGENTS BROKERS & SERVICES [6411]
		ORGANIZATION NAME:           	02 Finance
		EIN:				362151613
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		144
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	001-09761
		FILM NUMBER:		25973470

	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

REPORTING-OWNER:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Hudson Scott R
		CENTRAL INDEX KEY:			0001482241
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		144

	MAIL ADDRESS:	
		STREET 1:		C/O ARTHUR J. GALLAGHER & CO.
		STREET 2:		TWO PIERCE PLACE
		CITY:			ITASCA
		STATE:			IL
		ZIP:			60143
</SEC-HEADER>
<DOCUMENT>
<TYPE>144
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
  <headerData>
    <submissionType>144</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001482241</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0000354190</issuerCik>
      <issuerName>Arthur J. Gallagher &amp; Co.</issuerName>
      <secFileNumber>001-09761</secFileNumber>
      <issuerAddress>
        <com:street1>2850 GOLF ROAD</com:street1>
        <com:city>ROLLING MEADOWS</com:city>
        <com:stateOrCountry>IL</com:stateOrCountry>
        <com:zipCode>60008-4050</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>630-773-3800</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Hudson Scott R</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Officer</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>Fidelity Brokerage Services LLC</name>
        <address>
          <com:street1>900 Salem Street</com:street1>
          <com:city>Smithfield</com:city>
          <com:stateOrCountry>RI</com:stateOrCountry>
          <com:zipCode>02917</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>10500</noOfUnitsSold>
      <aggregateMarketValue>3540272.82</aggregateMarketValue>
      <noOfUnitsOutstanding>256100000</noOfUnitsOutstanding>
      <approxSaleDate>05/21/2025</approxSaleDate>
      <securitiesExchangeName>NYSE</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>05/21/2025</acquiredDate>
      <natureOfAcquisitionTransaction>Option Granted 03/14/2019</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>10500</amountOfSecuritiesAcquired>
      <paymentDate>05/21/2025</paymentDate>
      <natureOfPayment>Cash</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Scott R. Hudson</name>
        <address>
          <com:street1>2850 Golf Road</com:street1>
          <com:city>Rolling Meadows</com:city>
          <com:stateOrCountry>IL</com:stateOrCountry>
          <com:zipCode>60008</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>03/21/2025</saleDate>
      <amountOfSecuritiesSold>7510</amountOfSecuritiesSold>
      <grossProceeds>2505296.52</grossProceeds>
    </securitiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>05/21/2025</noticeDate>
      <signature>/s/ Margaret Campbell, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Scott R. Hudson</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
