FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.         
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES
                                                                                  
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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
                      

1. Name and Address of Reporting Person *

GALLAGHER J PATRICK JR
2. Issuer Name and Ticker or Trading Symbol

Arthur J. Gallagher & Co. [ AJG ]
5. Relationship of Reporting Person(s) to Issuer (Check all applicable)

__X__ Director                    _____ 10% Owner
__X__ Officer (give title below)    _____ Other (specify below)
CEO
(Last)          (First)          (Middle)

2850 GOLF ROAD
3. Date of Earliest Transaction (MM/DD/YYYY)

3/1/2026
(Street)

ROLLING MEADOWS, IL 60008-4002
4. If Amendment, Date Original Filed (MM/DD/YYYY)

 
6. Individual or Joint/Group Filing (Check Applicable Line)

_X _ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)        (State)        (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Trans. Date 2A. Deemed Execution Date, if any 3. Trans. Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security3. Trans. Date3A. Deemed Execution Date, if any4. Trans. Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
6. Date Exercisable and Expiration Date7. Title and Amount of Securities Underlying Derivative Security
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Non-qualified Stock Option $228.2 3/1/2026  A   48,449     (1)3/1/2033 Common Stock 48,449 $0 48,449 D  

Explanation of Responses:
(1) One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date.

Remarks:
Ex-24: Power of Attorney.

Reporting Owners
Reporting Owner Name / Address
Relationships
Director10% OwnerOfficerOther
GALLAGHER J PATRICK JR
2850 GOLF ROAD
ROLLING MEADOWS, IL 60008-4002
X
CEO

Signatures
/s/ Monica Norzagaray, by power of attorney3/3/2026
**Signature of Reporting PersonDate


Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note:File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

POWER OF ATTORNEY

Know by all these presents, that the undersigned hereby constitutes and appoints each of Walter D. Bay, Richard C. Cary, Seth Diehl, S. Lane Howell, Alex W. King and Monica Norzagaray, signing singly and with full power of substitution and re-substitution, as the undersigned?s true and lawful attorney-in-fact to:

1. Take any actions as may be necessary or appropriate to enable the undersigned to submit and file forms and other documents with the U.S. Securities and Exchange Commission (?SEC?) utilizing the SEC?s Electronic Data Gathering and Retrieval system or any successor filing system (?EDGAR?), which actions may include preparing, executing in the undersigned?s name and on the undersigned?s behalf, and submitting a Form ID application, amendments thereto, and such other documents and information as may be necessary or appropriate to obtain and maintain codes and passwords enabling the undersigned to make filings and submissions with the SEC utilizing EDGAR.

2. Act as an account administrator for the undersigned?s EDGAR account, including (a) acting as the EDGAR point of contact with respect to the undersigned?s EDGAR account, (b) appointing, removing and replacing account administrators, account users, technical administrators and delegated entities;
(c) delegating authority to entities, including filing agents, law firms, broker-dealers and related entities, to file on the undersigned?s behalf;
(d) maintaining the security of the undersigned?s EDGAR account dashboard, including modification of access codes; (e) maintaining, modifying and certifying the accuracy of information on the undersigned?s EDGAR account dashboard; and (f) taking any other actions contemplated by Rule 10 of Regulation S-T.

3. Cause Arthur J. Gallagher & Co. (the ?Company?) to accept a delegation of authority from any of the undersigned?s EDGAR account administrators and, pursuant to that delegation, authorize the Company?s EDGAR account administrators to appoint, remove or replace users for the undersigned?s EDGAR account.

4. Prepare, execute, for and on behalf of the undersigned, in the undersigned capacity as a director and/or officer of the Company, complete and file any and all forms and other documents (including any amendments thereto) the undersigned is required to file with the SEC, or which the attorney-in-fact considers advisable for the undersigned to file with the SEC, in accordance with Section 13 of the Securities Exchange Act of 1934 (the ?Exchange Act?) or any rule or regulation thereunder (?Section 13?), including Forms 13G and 13D, Section 16(a) of the Exchange Act or any rule or regulation thereunder (?Section 16?), including Forms 3, 4 and 5, or under Rule 144 under the Securities Act of 1933 (the ?Securities Act?) or any rule or regulation thereunder (?Rule 144?), including Form 144.

5. Take any other action of any type whatsoever in connection with the foregoing which, in the opinion of such attorney-in-fact, may be of benefit to, in the best interest of, or legally required by, the undersigned, it being understood that the documents executed by such attorney-in-fact on behalf of the undersigned pursuant to this Power of Attorney shall be in such form and shall contain such terms and conditions as such attorney-in-fact may approve in his or her sole discretion.

The undersigned hereby grants to each such attorney-in-fact full power and authority to do and perform any and every act and thing whatsoever requisite, necessary, or proper to be done in the exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all that such attorney-in-fact, or his or her substitute or substitutes, shall lawfully do or cause to be done by virtue of this power of attorney and the rights and powers herein granted. The undersigned acknowledges that the foregoing attorneys-in-fact, in serving in such capacity at the request of the undersigned, are not assuming any of the undersigned?s responsibilities to comply with the requirements of the Exchange Act or Securities Act, including Section 13, Section 16 or Rule 144.

This Power of Attorney shall remain in full force and effect until the earliest to occur of (a) the undersigned is no longer required to make filings under
Section 13, Section 16 or Rule 144 with respect to their holdings of and transactions in securities issued by the Company, (b) revocation by the undersigned in writing delivered to the foregoing attorneys-in-fact or
(c) as to any attorney-in-fact individually, until such attorney-in-fact is no longer employed by the Company or its subsidiaries.

IN WITNESS WHEREOF, I have hereunto set my hand this 29th day of October, 2025.

Signature: /s/ J. Patrick Gallagher Jr.
Name: J. Patrick Gallagher Jr.