AJG Arthur J Gallagher and Company

As filed with the Securities and Exchange Commission on August 4, 2023.

Registration No. 333-                

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

ARTHUR J. GALLAGHER & CO.

(Exact name of registrant as specified in its charter)

Arthur J. Gallagher & Co.

2850 W. Golf Road

Rolling Meadows, Il 60008

(Address of Principal Executive Offices, Zip Code)

Arthur J. Gallagher & Co. Deferred Equity Participation Plan

Arthur J. Gallagher & Co. Deferred Cash Participation Plan

Arthur J. Gallagher & Co. Supplemental Savings and Thrift Plan

(Full Title of the Plans)

Walter D. Bay, Esq.

Vice President, General Counsel and Secretary

2850 W. Golf Road

Rolling Meadows, Il 60008

(630) 773-3800

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Sean Feller

Gibson, Dunn & Crutcher LLP

2029 Century Park East, Suite 4000

Los Angeles, CA 90067-3026

(310) 552-8500

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

EXPLANATORY NOTE

This Registration Statement on Form S-8 is filed by Arthur J. Gallagher & Co. (the “Company”) for the purpose of registering an additional 4,000,000 shares of Common Stock, par value $1.00 per share, as well as $2,000,000,000 in unsecured obligations to pay deferred compensation in the future, to be offered and sold under the Arthur J. Gallagher & Co. Deferred Equity Participation Plan (the “DEPP”), the Arthur J. Gallagher & Co. Deferred Cash Participation Plan (the “DCPP”) and the Arthur J. Gallagher & Co. Supplemental Savings and Thrift Plan (the “Supplemental Plan,” together with the DEPP and the DCPP, the “Plans”). All shares registered hereunder in connection with the Plans are not newly issued shares of our common stock but, rather, represent shares that will be purchased in the open market by the institutional trustee for each of the Plans and issued (or sold, at the participant’s direction) to participants pursuant to the terms of such plans.

The total number of shares registered on this Form S-8 in connection with the Plans consists of the following: (i) 2,100,000 shares available for issuance under the DEPP; (ii) 900,000 shares available for issuance under the DCPP; and (iii) 1,000,000 shares available for issuance under the Supplemental Plan. The total amount of unsecured obligations to pay deferred compensation in the future registered on this Form S-8 in connection with the Plans consists of the following: (i) $650,000,000 under the DEPP; (ii) $250,000,000 under the DCPP; and (iii) $1,100,000,000 under the Supplemental Plan.

PART I

INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

The documents containing the information specified in Part I of Form S-8 have been or will be delivered to participants in the Plan as specified by Rule 428(b)(1) promulgated by the Securities and Exchange Commission (the “SEC”) under the Securities Act of 1933, as amended (the “Securities Act”). Such documents are not being filed by the Company with the SEC but constitute (along with the documents incorporated by reference into this registration statement pursuant to Item 3 of Part II hereof) a prospectus that meets the requirements of Section 10(a) of the Securities Act.

PART II

INFORMATION REQUIRED IN REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

The SEC’s rules allow the Company to incorporate by reference information into this Registration Statement. This enables the Company to disclose important information to you by referring you to another document. Any information referred to in this way is considered part of this Registration Statement from the date the Company files such document. Any reports filed by the Company with the SEC after the date of this Registration Statement, and before the date that the offering of the securities by means of this Registration Statement is terminated, will automatically update and, where applicable, supersede any information contained in this Registration Statement or incorporated by reference in this Registration Statement.

We incorporate by reference into this Registration Statement the following documents or information filed with the SEC (other than, in each case, documents or information deemed to have been furnished under Item 2.02 or Item 7.01 of Form 8-K, which is not deemed filed in accordance with SEC rules and is not incorporated by reference herein):

The Company will provide without charge to each person, including any beneficial owner, to whom this Registration Statement is delivered, upon his or her written or oral request, a copy of any or all documents referred to above which have been or may be incorporated by reference into this Registration Statement, excluding exhibits to those documents unless they are specifically incorporated by reference into those documents. You can obtain those documents from our website at www.ajg.com or request them in writing or by telephone at the following address or telephone number: General Counsel, Arthur J. Gallagher & Co., 2850 W. Golf Road, Rolling Meadows, Illinois 60008-4050; Telephone: (630) 773-3800. Except for the information specifically incorporated into this Registration Statement by reference as set forth above, information contained on our website is not a part of this Registration Statement.

Item 4. Description of Securities.

Deferred Equity Participation Plan (DEPP)

The DEPP is a non-qualified deferred compensation plan that generally provides for distributions to certain key executives when they reach age 62 (or the one-year anniversary of the date of the grant for participants over the age of 61 as of the grant date) or upon or after their actual retirement. Under the provisions of the DEPP, the Company typically contributes cash, in an amount determined by the Compensation Committee of the Board of Directors of the Company, to an institutional trustee on behalf of the executives participating in the plan, and instructs the trustee to acquire a specified number of shares of Company common stock on the open market or in privately negotiated transactions based on participant elections.

The obligations of the Company under the DEPP (the “DEPP Obligations”) are unsecured general obligations of the Company to pay the compensation deferred in accordance with the terms of the DEPP, along with any interest deemed to accrue on the deferrals, and will rank equally with other unsecured and unsubordinated indebtedness of the Company from time to time outstanding.

The Compensation Committee of the Board of Directors establishes from time to time the hypothetical investment(s) made available under the DEPP, which may include investments in the Company’s common stock, for purposes of valuing participant accounts.

The Board of Directors of the Company reserves the right to amend or terminate the DEPP at any time.

The DEPP Obligations are not convertible into another security of the Company. The DEPP Obligations will not have the benefit of a negative pledge or any other affirmative or negative covenant on the part of the Company.

Deferred Cash Participation Plan (DCPP)

The DCPP is a non-qualified deferred compensation plan for certain key employees, other than executive officers, that generally provides for vesting and/or distributions no sooner than five years from the date of awards (or such other date as determined by the administrator). Under the provisions of the DCPP, the Company typically contributes cash, in an amount determined by the Compensation Committee of the Board of Directors of the Company, to an institutional trustee on behalf of the employees participating in the plan, and instructs the trustee to acquire a specified number of shares of Company common stock on the open market or in privately negotiated transactions based on participant elections.

The obligations of the Company under the DCPP (the “DCPP”) are unsecured general obligations of the Company to pay the compensation deferred in accordance with the terms of the DCPP, along with any interest deemed to accrue on the deferrals, and will rank equally with other unsecured and unsubordinated indebtedness of the Company from time to time outstanding.

The Compensation Committee of the Board of Directors establishes from time to time the hypothetical investment(s) made available under the DCPP, which may include investments in the Company’s common stock, for purposes of valuing participant accounts.

The Board of Directors of the Company reserves the right to amend or terminate the DCPP at any time.

The DCPP Obligations are not convertible into another security of the Company. The DCPP Obligations will not have the benefit of a negative pledge or any other affirmative or negative covenant on the part of the Company.

Supplemental Savings and Thrift Plan (Supplemental Plan)

The Supplemental Plan is a non-qualified deferred compensation plan that allows certain highly compensated employees to defer a portion of their compensation until their retirement or a future date. The Company makes matching contributions to the Supplemental Plan (up to a maximum of the lesser of a participant’s elective deferral of base salary, annual bonus, quarterly bonuses and commissions or 5.0% of eligible compensation, less matching amounts contributed under the Company’s 401(k) plan), at the discretion of the Board of Directors.

The obligations of the Company under the Supplemental Plan (the “Supplemental Plan Obligations”) are unsecured general obligations of the Company to pay the compensation deferred in accordance with the terms of the Supplemental Plan, along with any interest deemed to accrue on the deferrals, and will rank equally with other unsecured and unsubordinated indebtedness of the Company from time to time outstanding.

The Compensation Committee of the Board of Directors establishes from time to time the hypothetical investment(s) made available under the Supplemental Plan, which may include investments in the Company’s common stock, for purposes of valuing participant accounts.

The Board of Directors of the Company reserves the right to amend or terminate the Supplemental Plan at any time.

The Supplemental Plan Obligations are not convertible into another security of the Company. The Supplemental Plan Obligations will not have the benefit of a negative pledge or any other affirmative or negative covenant on the part of the Company.

Item 5. Interests of Named Expert and Counsel.

Not applicable.

Item 6. Indemnification of Directors and Officers.

The Company is incorporated under the Delaware General Corporation Law (the “DGCL”).

Section 145(a) of the DGCL provides that a Delaware corporation shall have the power to indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation) by reason of the fact that the person is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by the person in connection with such action, suit or proceeding if the person acted in good faith and in a manner the person reasonably believed to be in or not opposed to the best interests of the corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe the person’s conduct was unlawful.

Section 145(b) of the DGCL provides that a Delaware corporation shall have the power to indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action or suit by or in the right of the corporation to procure a judgment in its favor by reason of the fact that such person acted in any of the capacities set forth above, against expenses (including attorneys’ fees) actually and reasonably incurred by the person in connection with the defense or settlement of such action or suit if the person acted under standards similar to those discussed above, except that no indemnification shall be made in respect of any claim, issue or matter as to which such person shall have been adjudged to be liable to the corporation unless and only to the extent that the Court of Chancery or the court in which such action or suit was brought shall determine that despite the adjudication of liability, such person is fairly and reasonably entitled to be indemnified for such expenses which the Court of Chancery or such other court shall deem proper.

Section 145 of the DGCL further provides that to the extent a current or former director or officer of a corporation has been successful on the merits or otherwise in defense of any action, suit or proceeding referred to in subsections (a) and (b) or in the defense of any claim, issue or matter therein, such person shall be indemnified against expenses (including attorneys’ fees) actually and reasonably incurred by such person in connection therewith; and that indemnification provided for by Section 145 shall not be deemed exclusive of any other rights to which the indemnified party may be entitled; and that the corporation shall have power to purchase and maintain insurance on behalf of a director or officer of the corporation against any liability asserted against such person and incurred by such person in any such capacity or arising out of such person’s status as such whether or not the corporation would have the power to indemnify such person against such liability under Section 145.

Section 102(b)(7) of the DGCL provides that a corporation may eliminate or limit the personal liability of a director or officer to the corporation or its stockholders for monetary damages for breach of fiduciary duty as a director or officer, provided that such provisions shall not eliminate or limit the liability of (1) a director for any breach of the director’s duty of loyalty to the corporation or its stockholders, (2) a director for acts or omissions not in good faith or that involve intentional misconduct or a knowing violation of law, (3) a director under section 174 of the DGCL; (4) for any transaction from which the director derived an improper personal benefit; or (5) an officer in any action by or in the right of the corporation. No such provision shall eliminate or limit the liability of a director for any act or omission occurring before the date when such provision becomes effective.

Article Seven of the Company’s Amended and Restated By-laws and Article Twelfth of the Company’s Restated Certificate of Incorporation provide for the indemnification of each of the Company’s directors, officers, employees or agents to the full extent permitted by the DGCL or other applicable laws presently or hereafter in effect.

Article Seven of the Company’s Amended and Restated By-laws provides that the Company shall indemnify any person in connection with any action, suit or proceeding brought or threatened by reason of the fact that he or she is or was one of the Company’s directors, officers, employees or agents, or is or was serving at the Company’s request as a director, officer, employee or agent of another enterprise, against all costs actually and reasonably incurred by him or her in connection with such action, suit or proceeding if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the Company’s best interests and, with respect to any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful. Similar indemnity is permitted to be provided to such persons in connection with an action or suit by the Company or in the Company’s right, and provided further that such person shall not have been adjudged liable for negligence or misconduct in the performance of his or her duty to the Company, unless, in view of all the circumstances of the case, the court in which the action or suit was brought determines that such person despite the adjudication of liability is fairly and reasonably entitled to indemnity for such expenses.

Article Twelfth of the Company’s Restated Certificate of Incorporation eliminates the liability of the Company’s directors for monetary damages for breach of fiduciary duty as a director except where a director breaches his or her duty of loyalty to the Company and its stockholders, fails to act in good faith or engages in intentional misconduct or a knowing violation of law, authorizes the payment of a dividend or stock repurchase that is illegal under Section 174 of the DGCL, or obtains an improper personal benefit. Article Twelfth of the Company’s Restated Certificate of Incorporation also eliminates the liability of the Company’s officers for monetary damages for breach of fiduciary duty as an officer except where an officer breaches his or her duty of loyalty to the Company and its stockholders, fails to act in good faith or engages in intentional misconduct or a knowing violation of law, obtains an improper personal benefit, or in any action by or in the right of the Company.

The Company also maintains and pays premiums on a directors’ and officers’ liability insurance policy and has entered into indemnity agreements with its directors and officers. The provisions of each indemnity agreement alter or clarify the statutory indemnification in the following respects: (1) indemnity will be explicitly provided for settlements in derivative actions; (2) prompt payment of litigation expenses will be provided in advance of indemnification; (3) prompt indemnification of advances of expenses will be provided unless a determination is made that the director or officer has not met the required standard; (4) the director or officer will be permitted to petition a court to determine whether his or her actions meet the standards required; and (5) partial indemnification will be permitted in the event that the director or officer is not entitled to full indemnification. In addition, each indemnity agreement specifically includes indemnification with respect to actions, suits or proceedings brought under and/or predicated upon the Securities Act of 1933, as amended, and/or the Securities Exchange Act of 1934, as amended.

The preceding summary is qualified in its entirety by the Company’s Restated Certificate of Incorporation and Amended and Restated By-laws, and the indemnity agreements described above.

Item 7. Exemption from Registration Claimed.

Not applicable.

Item 8. Exhibits.

Item 9. Undertakings.

(a) The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) of this section do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered that remain unsold at the termination of the offering.

(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in this registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Rolling Meadows, State of Illinois, on this 4th day of August, 2023.

POWER OF ATTORNEY

We, the undersigned directors and officers, do hereby severally constitute and appoint Walter D. Bay and Douglas K. Howell, and each of them severally, our true and lawful attorneys-in-fact and agents, to do any and all acts and things in our name and on our behalf in our capacities as directors and officers and to execute any and all instruments for us and in our names in the capacities indicated below, which said attorneys-in-fact and agents may deem necessary or advisable to enable Arthur J. Gallagher & Co. to comply with the Securities Act of 1933, as amended (the “Securities Act”), and any rules, regulations and requirements of the Securities and Exchange Commission, in connection with this registration statement on Form S-8, including specifically, but without limitation, power and authority to sign for us or any of us, in our names in the capacities indicated below, any and all amendments (including pre- and post- effective amendments) hereto and any related registration statement and amendments thereto; and we do each hereby ratify and confirm all that said attorneys-in-fact and agents shall do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities and on the dates indicated.

Exhibit 4.7

ARTHUR J. GALLAGHER & CO.

DEFERRED CASH PARTICIPATION PLAN

AWARD AGREEMENT

Important: Not accepting this Award by the Acceptance Deadline may result in forfeiture.

This Deferred Cash Participation Plan Award Agreement (this “Agreement”), effective as of the Award Date shown above, between Arthur J. Gallagher & Co., a Delaware corporation (the “Company”), and the Participant named above, sets forth the terms and conditions of an Annual Discretionary Allocation (the “Award”) under the Arthur J. Gallagher & Co. Deferred Cash Participation Plan (the “Plan”). The Award is subject to all of the terms and conditions set forth in the Plan and this Agreement. In the event of any conflict, the Plan will control over this Agreement. Capitalized terms in this Agreement shall have the meaning specified in the Plan, unless a different meaning is specified herein. The Participant hereby expressly acknowledges receipt of a copy of the Plan.

1. Annual Discretionary Allocation. The Company hereby grants to the Participant the Annual Discretionary Allocation in the amount specified above.

2. Vesting. The Award shall become vested as set forth in Section 4(c) of the Plan. In the event the Participant’s employment with the Company terminates for any reason prior to the Vesting Date, then the Award shall automatically terminate and be forfeited, cancelled and of no further force and effect.

3. Payment. Not later than 30 calendar days immediately following the Award Date, or such earlier date specified by the Administrator, the Participant shall make a distribution election by executing an Annual Distribution Form which shall specify the Distribution Date and the Payment Form for the Award. Pursuant to Section 5(a)(iv) of the Plan, if the Participant fails to make such elections within such period, he or she shall be deemed to have elected to receive a lump-sum payment in the calendar year that includes the Vesting

Date. A Participant may change his or her Distribution Election only in accordance with the provisions set forth in Section 5(b) of the Plan.

(a) Distribution Date. Pursuant to Section 5(a)(ii) of the Plan, the Participant’s Distribution Election shall specify one of the following as the Participant’s Distribution Date: (i) the six-month anniversary of the date on which the Participant undergoes a Separation from Service with the Company; or (ii) a specified year no earlier than the calendar year that includes the Vesting Date. Section 5(c) of the Plan specifies the timing of the distribution payments. Payments may be accelerated only upon the occurrence of an event described in Section 6, 10(b), or 10(c) of the Plan.

(b) Payment Form. Pursuant to Section 5(a)(iii) of the Plan, the Participant’s Distribution Election shall specify that the Award will be paid in the form of: (i) a lump-sum payment; (ii) ten substantially equal annual installment payments commencing on the Distribution Date, and due on the next nine anniversaries of the Distribution Date; or (iii) five substantially equal annual installment payments commencing on the Distribution Date, and due on the next four anniversaries of the Distribution Date.

(c) Investment and Medium of Payment. The Participant may make an election to receive his or her Award in the form of shares of common stock of the Company (“Common Stock”) or cash. The Participant acknowledges that the default election is to receive the Award in the form of Common Stock, and that by signing this Agreement (or failing to make an election by the date this Award Agreement is due to be signed and returned – see above) he or she makes the default election irrevocably with respect to the Award. The Participant further acknowledges that he or she must call (630) 285-3955 for an alternate form, prior to signing this Agreement, if he or she wishes to make an election other than the default election, and that any such alternate election must be made by the date this Award Agreement is due to be signed and returned.

4. Earnings. Distributions will reflect the hypothetical investment performance of amounts credited to the Participant’s Annual Account as described in Section 4(d) of the Plan.

5. Miscellaneous.

(a) Administration. Any action taken or decision made by the Company or the Administrator or its delegates arising out of or in connection with the construction, administration, interpretation, or effect of the Plan or this Agreement shall lie within its sole and absolute discretion, as the case may be, and shall be final, conclusive, and binding upon the Participant and all persons claiming under or through the Participant. By accepting the Award or other benefit under the Plan, the Participant and each person claiming under or through the Participant shall be conclusively deemed to have indicated acceptance and ratification of, and consent to, any action taken or decision made under the Plan by the Company or the Administrator or its delegates.

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(b) Tax Withholding and Furnishing of Information. There shall be withheld from any payment under this Agreement such amount, if any, as the Company determines is required by law, including, but not limited to, U.S. federal, state, local or foreign income, employment, or other taxes or social security liabilities incurred by reason of making of the Award or of such payment. It shall be a condition to the obligation of the Company to make payments under this Agreement that the Participant promptly provide the Company with all forms, documents or other information reasonably required by the Company in connection with the Award.

(c) Delay of Payment. Any payment to be made to the Participant under the Award and this Agreement will be subject to the Company’s right to delay payment in the event that the Company reasonably anticipates that it would not be permitted to deduct such payment by reason of Section 162(m) of the Code. In addition, by accepting this Award and executing this Agreement, the Participant hereby voluntarily acknowledges and consents to a delay by the Company pursuant to this section of any payment under the Awards granted to the Participant under the Plan prior to the date of this Agreement. The Participant acknowledges that as required by Section 409A, the Participant may not determine or elect whether the Company delays any payment pursuant to this section.

(d) Clawback, Forfeiture, or Recoupment. Any payment made to the Participant under the Award will be subject to the restrictive covenants in Section 8 of the Plan, the Company’s compensation recovery policy, the forfeiture provisions of Section 7(b) of the Plan, as well as any other or additional “clawback,” forfeiture, or recoupment policy now existing or adopted by the Company after the date of this Agreement.

(e) Exception to Confidentiality Provision. Notwithstanding the generality of the prohibitions in the Plan relating to confidential information, the Participant acknowledges that nothing in this Agreement prohibits the Participant from reporting possible violations of federal law or regulation to any governmental agency or entity including, without limitation, the Department of Justice, the Securities and Exchange Commission, Congress, and any agency of the Inspector General, or making other disclosures that are protected under the whistleblower provisions of federal law or regulation.

(f) Beneficiary Designation. The Participant may, by completing and returning the appropriate form provided to the Participant by the Company, name a beneficiary or beneficiaries to receive any payment to which he or she may become entitled under this Agreement in the event of his or her death under the circumstances described in, and in accordance with, Section 19 of the Plan. The Participant may change his or her beneficiary or beneficiaries from time to time by submitting a new form in accordance with the procedures established by the Company. If the Participant does not designate a beneficiary, or if no designated beneficiary is living on the date any amount becomes payable under this Agreement, such payment will be made to the legal representatives of the Participant’s estate, which will be deemed to be the Participant’s designated beneficiary under this Agreement.

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(g) Section 409A. This Agreement and the payment of the Award hereunder are intended to comply with the requirements of Section 409A of the Internal Revenue Code of 1986, as amended, and the Treasury Regulations promulgated and other official guidance issued thereunder, and this Agreement shall be administered and interpreted consistent with such intent.

(h) Governing Law. This Agreement, the Award, and all determinations made and actions taken pursuant thereto, to the extent not otherwise governed by the laws of the United States, shall be governed by the laws of the State of Delaware and construed in accordance therewith without giving effect to principles of conflicts of laws.

(signature page immediately follows)

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IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the day and year first above written.

ARTHUR J. GALLAGHER & CO.
By:
Walter D. Bay
Vice President, General Counsel and Secretary
PARTICIPANT

5

Exhibit 5.1

August 4, 2023

Arthur J. Gallagher & Co.

2850 W. Golf Road

Rolling Meadows, Il 60008

Re: Registration Statement on Form S-8

Ladies and Gentlemen:

We have examined the Registration Statement on Form S-8 (the “Registration Statement”), of Arthur J. Gallagher & Co., a Delaware corporation (the “Company”), to be filed with the Securities and Exchange Commission (the “Commission”) pursuant to the Securities Act of 1933, as amended (the “Securities Act”), in connection with the offering by the Company of up to (i) 2,100,000 shares (the “DEPP Shares”) of the Company’s Common Stock, par value $1.00 per share (“Common Stock”), available for issuance pursuant to the Arthur J. Gallagher & Co. Deferred Equity Participation Plan (the “DEPP”), (ii) 900,000 shares (the “DCPP Shares”) of Common Stock available for issuance pursuant to the Arthur J. Gallagher & Co. Deferred Cash Participation Plan (the “DCPP”), (iii) 1,000,000 shares (the “Supplemental Plan Shares,” and together with the DEPP Shares and the DCPP Shares, collectively, the “Shares”) of Common Stock available for issuance pursuant to the Arthur J. Gallagher & Co. Supplemental Savings and Thrift Plan (the “Supplemental Plan” and together with the DEPP and the DCPP, the “Plans”) and (iv) unsecured obligations to pay deferred compensation in the future in accordance with the terms of the applicable Plan, in the following amounts: (i) $650,000,000 under the DEPP; (ii) $250,000,000 under the DCPP; and (iii) $1,100,000,000 under the Supplemental Plan (the “Deferred Compensation Obligations”).

In arriving at the opinion expressed below, we have examined originals, or copies certified or otherwise identified to our satisfaction as being true and complete copies of the originals, of the Plans and such other documents, corporate records of the Company, certificates of officers of the Company and of public officials and other documents as we have deemed necessary or advisable to enable us to render this opinion. In our examination, we have assumed without independent investigation the genuineness of all signatures, the legal capacity and competency of all natural persons, the authenticity of all documents submitted to us as originals and the conformity to original documents of all documents submitted to us as copies. We have also assumed that there are no agreements or understandings between or among the Company and any participants in the Plans that would expand, modify or otherwise affect the terms of the Plans or the respective rights or obligations of the participants thereunder. Finally, we have assumed the accuracy of all other information provided to us by the Company during the course of our investigations, on which we have relied in issuing the opinion expressed below.

Abu Dhabi • Beijing • Brussels • Century City • Dallas • Denver • Dubai • Frankfurt • Hong Kong • Houston • London • Los Angeles

Munich • New York • Orange County • Palo Alto • Paris • San Francisco • Singapore • Washington, D.C.

Arthur J. Gallagher & Co.

August 4, 2023

Page 2

Based upon the foregoing, and subject to the assumptions, exceptions, qualifications and limitations set forth herein and in reliance on the statements of fact contained in the documents that we have examined, we are of the opinion that: (i) the Shares, when issued and sold in accordance with the terms set forth in the Plans and against payment therefore, and when the Registration Statement has become effective under the Securities Act, will be validly issued, fully paid and non-assessable, and (ii) the Deferred Compensation Obligations, when issued in accordance with the terms of the Plans, will constitute legal, valid and binding obligations of the Company.

We render no opinion herein as to matters involving the laws of any jurisdiction other than the Delaware General Corporation Law (the “DGCL”). This opinion is limited to the effect of the current state of the DGCL and to the facts as they currently exist. We assume no obligation to revise or supplement this opinion in the event of future changes in such laws or the interpretations thereof or such facts.

We consent to the filing of this opinion as an exhibit to the Registration Statement. In giving these consents, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act or the Rules and Regulations of the Commission.

Very truly yours,

/s/ Gibson, Dunn & Crutcher LLP

Gibson, Dunn & Crutcher LLP

Abu Dhabi • Beijing • Brussels • Century City • Dallas • Denver • Dubai • Frankfurt • Hong Kong • Houston • London • Los Angeles

Munich • New York • Orange County • Palo Alto • Paris • San Francisco • Singapore • Washington, D.C.

Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the Arthur J. Gallagher & Co. Deferred Equity Participation Plan, Arthur J. Gallagher & Co. Deferred Cash Participation Plan, and the Arthur J. Gallagher & Co. Supplemental Savings and Thrift Plan of our reports dated February 10, 2023, with respect to the consolidated financial statements of Arthur J. Gallagher & Co. and the effectiveness of internal control over financial reporting of Arthur J. Gallagher & Co. included in its Annual Report (Form 10-K) for the year ended December 31, 2022, filed with the Securities and Exchange Commission.

/s/ Ernst & Young LLP

Chicago, Illinois

August 4, 2023

Exhibit 107.1

Form S-8

(Form Type)

ARTHUR J. GALLAGHER & CO.

(Exact Name of Registrant as Specified in its Charter)

Table 1: Newly Registered Securities