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): June 17, 2022

Aon plc

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: +353 1 266 6000

Former name or former address, if changed since last report: Not Applicable

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):

Securities registered pursuant to Section 12(b) of the Act:

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.  ☐

On June 21, 2022, Aon Corporation, an indirect, wholly owned subsidiary of Aon plc, and Christa Davies entered into an amendment (the “Davies Amendment”) to the international assignment letter agreement dated July 1, 2016 between Aon Corporation and Ms. Davies (the “Davies International Assignment Letter”). The Davies Amendment extends the term of the Davies International Assignment Letter, which was set to expire on June 30, 2022, to expire on June 30, 2023.

On June 21, 2022, Aon Corporation 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 (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, 2022, to expire on June 30, 2023.

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

The Company held its Annual General Meeting of Shareholders (the “Annual Meeting”) on June 17, 2022. A total of 193,856,072 Class A Ordinary shares, or 91.15%, of the total shares entitled to vote, were represented at the Annual Meeting in person or by proxy.

Shareholders voted on the following five proposals at the Annual Meeting, all of which are described in the Company’s proxy statement for the Annual Meeting (the “Proxy Statement”), and cast their votes as described below:

(d) Exhibits.

*    *    *    *

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.