Submission of Matters to a Vote of Security Holders Form 8 K

Item 5.02

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

Amendment to International Assignment Letter

On June 24, 2024, Aon Corporation ("Aon Corporation"), an indirect, wholly owned subsidiary of Aon plc (together with its subsidiaries, "Aon" or the "Company"), and Gregory C. Case entered into an amendment (the "Case Amendment") to the international assignment letter agreement dated July 1, 2016 between Aon Corporation and Mr. Case (as amended, the "Case International Assignment Letter"). The Case Amendment extends the term of the Case International Assignment Letter, which was set to expire on June 30, 2024, to expire on June 30, 2025.

Transition Agreement

Reference is hereby made to the Current Report on Form 8-Kfiled by the Company on April 3, 2024, which disclosed Christa Davies' intention to retire from her position as Executive Vice President and Chief Financial Officer of the Company effective in the third quarter of 2024 and that Ms. Davies would serve as a senior advisor for a transition period thereafter.

On June 24, 2024, Aon Corporation entered into a letter agreement with Christa Davies in connection with such transition (the "Transition Agreement"). Under the Transition Agreement, Ms. Davies is expected to continue to serve in her current role as Executive Vice President and Chief Financial Officer through July 29, 2024, or such other date mutually agreed between Ms. Davies and Aon Corporation (the "Transition Start Date"), receiving her regular salary and benefits through the Transition Start Date, after which point she will cease to serve as Aon's Executive Vice President and Chief Financial Officer.

Ms. Davies will serve as a senior advisor to Aon during the period from the day after the Transition Start Date until and inclusive of May 31, 2026, unless Ms. Davies' employment is terminated earlier in accordance with the terms of the Transition Agreement (such period, the "Transition Period").

For service during the Transition Period, Ms. Davies will be entitled to: (i) earn a base salary at a rate of $500,000 per year; (ii) participate in Aon Corporation's employee benefit plans and paid time off programs generally available to similarly-situated full time senior executives; and (iii) continued vesting of Ms. Davies' existing Aon equity awards, other than Ms. Davies' special Performance Share Unit award granted on July 26, 2023, which Ms. Davies will forfeit in its entirety on the day after the Transition Start Date. Such continued equity award vesting will generally be in accordance with the terms of the equity awards' underlying award agreements, except no "Good Reason" (as defined in the applicable award agreement or employment documentation) vesting or acceleration will apply to such awards during the Transition Period.

In addition, Ms. Davies is eligible to (i) receive a cash pro-rataannual incentive bonus for fiscal year 2024 based on Aon's and Ms. Davies' actual performance for fiscal 2024, but pro-ratedto reflect the portion of the year Ms. Davies serves as Executive Vice President and Chief Financial Officer, subject to Ms. Davies' continued employment with Aon on the bonus payment date and her provision of transition services and (ii) receive payment or reimbursement from Aon for tax return preparation services up to and including the United Kingdom 2024/25 tax year and the United States 2024 tax year.

The Transition Agreement also extends the international assignment letter agreement dated July 1, 2016 between Aon Corporation and Ms. Davies through the Transition Start Date, clarifies that her transition to the role of senior advisor will not trigger repayment obligations thereunder, and waives certain other repayment obligations under the international assignment letter.

In addition, during the Transition Period, Ms. Davies will not be eligible to (a) receive or earn any Aon annual incentive compensation plan bonuses other than the pro-rataannual incentive bonus for fiscal year 2024; (b) be granted any Aon equity or equity-based awards; or (c) participate in the Severance Plan (as defined in the Transition Agreement) or receive severance under her prior employment agreement.

The Transition Agreement also provides that Ms. Davies is subject to non-competition,non-solicitation,confidentiality and non-disparagementrestrictive covenants and cooperation covenants and that she is required to timely execute and not revoke a release of claims against Aon.

Ms. Davies' employment with Aon Corporation will terminate at the end of the Transition Period. Under the Transition Agreement, Ms. Davies' employment with Aon may be terminated during the Transition Period with three months' notice by Ms. Davies or Aon Corporation, provided that Aon Corporation may provide pay in lieu of notice. Under select circumstances, Ms. Davies and Aon Corporation may also terminate Ms. Davies' employment without notice.

The foregoing summaries are qualified in their entirety by reference to the Case Amendment and the Transition Agreement, copies of which are attached as Exhibits 10.1 and 10.2, respectively, to this Current Report on Form 8-Kand incorporated herein by reference.