Executive Change

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549     FORM 8-K     CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 13, 2025     Aon plc (Exact Name of Registrant as Specified in Charter)       Ireland   1-7933   98-1539969 (State or Other Jurisdiction of Incorporation)   (Commission File Number)   (IRS Employer Identification No.) 15 George’s Quay , Dublin 2 , Ireland D02 VR98 (Address of principal executive offices) (Zip Code) Registrant’s telephone number, including area code: + 353 1 266 6000 Not Applicable (Former Name or Former Address, if Changed Since Last Report)     Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions ( see General Instruction A.2. below):   ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)   ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)   ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))   ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act:   Title of each class   Trading Symbol(s)   Name of each exchange on which registered Class A Ordinary Shares $0.01 nominal value   AON   New York Stock Exchange Guarantees of Aon plc’s 3.875% Senior Notes due 2025   AON25   New York Stock Exchange Guarantees of Aon plc’s 2.875% Senior Notes due 2026   AON26   New York Stock Exchange Guarantees of Aon Corporation and Aon Global Holdings plc’s 2.85% Senior Notes due 2027   AON27   New York Stock Exchange Guarantees of Aon North America, Inc.’s 5.125% Senior Notes due 2027   AON27B   New York Stock Exchange Guarantees of Aon North America, Inc.’s 5.150% Senior Notes due 2029   AON29   New York Stock Exchange Guarantees of Aon Corporation and Aon Global Holdings plc’s 2.05% Senior Notes due 2031   AON31   New York Stock Exchange Guarantees of Aon Corporation and Aon Global Holdings plc’s 2.60% Senior Notes due 2031   AON31A   New York Stock Exchange Guarantees of Aon North America, Inc.’s 5.300% Senior Notes due 2031   AON31B   New York Stock Exchange Guarantees of Aon Corporation and Aon Global Holdings plc’s 5.00% Senior Notes due 2032   AON32   New York Stock Exchange Guarantees of Aon Corporation and Aon Global Holdings plc’s 5.35% Senior Notes due 2033   AON33   New York Stock Exchange Guarantees of Aon North America, Inc.’s 5.450% Senior Notes due 2034   AON34   New York Stock Exchange Guarantees of Aon plc’s 4.25% Senior Notes due 2042   AON42   New York Stock Exchange Guarantees of Aon plc’s 4.45% Senior Notes due 2043   AON43   New York Stock Exchange Guarantees of Aon plc’s 4.60% Senior Notes due 2044   AON44   New York Stock Exchange Guarantees of Aon plc’s 4.75% Senior Notes due 2045   AON45   New York Stock Exchange Guarantees of Aon Corporation and Aon Global Holdings plc’s 2.90% Senior Notes due 2051   AON51   New York Stock Exchange Guarantees of Aon Corporation and Aon Global Holdings plc’s 3.90% Senior Notes due 2052   AON52   New York Stock Exchange Guarantees of Aon North America, Inc.’s 5.750% Senior Notes due 2054   AON54   New York Stock Exchange Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company  ☐ 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 13(a) of the Exchange Act. ☐       Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. On March 13, 2025, Aon plc (the “Company”) announced that Michael Neller will transition from his role as Chief Accounting Officer and Global Controller of the Company into a new role as Deputy Global Chief People Officer, Total Rewards and Talent Development of the Company. The Company is planning to conduct a search process to identify a new Chief Accounting Officer and Global Controller. Mr. Neller will continue to serve as the Company’s Chief Accounting Officer and Global Controller until a successor is appointed.   SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.   Aon plc By:   /s/ Darren Zeidel Name:   Darren Zeidel Title:   Executive Vice President, General Counsel and Company Secretary Date: March 13, 2025