POWER OF ATTORNEY

Know all by these presents, that the undersigned hereby constitutes and
appoints each of Walter D. Bay, Richard C. Cary, Seth Diehl, Ryan
Session and Monica Norzagaray his true and lawful attorney-in-fact to:

1.	execute and file for and on behalf of the undersigned the Form ID
Uniform Application for Access Codes to File on EDGAR;
2.	execute for and on behalf of the undersigned Forms 3, 4, and 5 in
accordance with Section 16(a) of the Securities Exchange Act of 1934 and the
rules thereunder;
3.	do and perform any and all acts for and on behalf of the undersigned which
may be necessary or desirable to complete and execute any such Form 3, 4,
or 5, complete and execute any amendment or amendments thereto, and timely
file such form with the United States Securities and Exchange Commission and
any other authority; and
4.	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 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 Section 16 of the Securities
Exchange Act of 1934.

This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, and 5 with respect to
his holdings of and transactions in securities issued by
Arthur J. Gallagher & Co., unless earlier revoked by the undersigned in a
signed writing delivered to the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 26 day of July, 2023.

__/s/ Christopher E. Mead_
                 Signature

_Christopher E. Mead____