DEF 14A of Aon plc, Apr 28, 2026

DEF 14A of Aon plc

Filed Apr 28, 2026 · FY20250001193125-26-187428

Open on EDGAR

  1. Director Nominee Composition

    Director Nominee Composition

  2. Director Nominee Composition

    | Diversity of Skills and Experiences: | | | | | | Business Continuity | Corporate Governance | Corporate Social Responsibility | Financial Acumen | Global Perspective | | Government and Public Policy | Human Capital Management | Investment & M&A | Innovation & Strategy | Legal & Regulatory | | | Professional/Financial Services | Risk Management | Technology, Data Privacy & Cybersecurity | |

  3. Director Nominee Composition

    Our Governance/Nominating Committee also considers a number of demographic and other factors in seeking to develop a Board that, as a whole, has the appropriate background, skills and experiences in the context of the needs of the Board. As part of our ongoing Board refreshment process, we welcomed one new independent director in 2025 and two new independent directors in 2024, with a total of five new independent directors joining the Board since 2022, and eight new independent directors since 2016. Directors

  4. Director Nominee Composition

    | | Name | Age | Director Since | Current Committee Membership | Other Boards† | | | Lester B. Knight, Chair* | 67 | 1999 | Executive Committee - Chair Governance/Nominating Committee - Chair People & Wellbeing Sub-Committee | — | | | Gregory C. Case, President and CEO | 63 | 2005 | Executive Committee People & Wellbeing Sub-Committee | — | | | Jose Antonio Álvarez* | 66 | 2024 | Audit Committee Organization and Compensation Committee | 1 | | | Jin-Yong Cai* | 66 | 2016 | Finance Committee - Chair Executive Committee Organization and Compensation Committee | — | | | Jeffrey C. Campbell* | 65 | 2018 | Audit Committee - Chair Executive Committee Organization and Compensation Committee | 2 | | | Cheryl A. Francis* | 72 | 2010 | People & Wellbeing Sub-Committee - Chair Governance/Nominating Committee Finance Committee Organization and Compensation Committee | 2 | | | Jo Ann Jenkins* | 68 | 2025 | Audit Committee | 2 | | | Adriana Karaboutis* | 63 | 2022 | Audit Committee Governance/Nominating Committee | 3 | | | Richard C. Notebaert* | 78 | 1998 | Executive Committee Finance Committee Governance/Nominating Committee People & Wellbeing Sub-Committee Organization and Compensation Committee | — | | | Gloria Santona* | 75 | 2004 | Audit Committee Governance/Nominating Committee People & Wellbeing Sub-Committee | — | | | Sarah E. Smith* | 67 | 2023 | Finance Committee People & Wellbeing Sub-Committee | 3 | | | Byron O. Spruell* | 61 | 2020 | Organization and Compensation Committee - Chair Executive Committee Audit Committee People & Wellbeing Sub-Committee | — | | | Admiral James G. Stavridis* | 70 | 2024 | Finance Committee | 1 |

  5. Director Nominee Composition

    * Independent director † Number of current other public company directorships or listed business development company trusteeships Corporate Governance Highlights Aon’s commitment to effective corporate governance is integral to our business. Highlights of our strong corporate governance practices include:

  6. Director Nominee Composition

    | Annual election of all directors and active Board refreshment | Separation of Board Chair and CEO | Strong Board oversight of risk management programs | | 12 of 13 directors are independent | Directors elected by a majority of votes cast in an uncontested election | Active shareholder engagement | | Regular executive sessions of the Board and its committees | Shareholder ability to call a special meeting | Robust share ownership guidelines for directors and senior executives | | Annual evaluation process for the Board, Committees, and individual directors | Corporate Governance Guidelines include Board oversight of director commitments and “overboarding” limitations | Comprehensive director orientation program |

  7. Director Nominee Composition

    2025 Executive Compensation Highlights The core principle of our executive compensation program continues to be pay for performance, as we continue towards our goal of being the leading global professional services firm focused on risk, health, and wealth. Leadership Performance Program. In early 2026, we settled performance share units (“PSUs”) granted to our NEOs in 2023 under our eighteenth LPP cycle (“LPP 18”). The settlement of those units in Class A Ordinary Shares was contingent upon achieving adjusted diluted earnings per share of at least $42.63 (threshold performance) over the performance period from January 1, 2023 to December 31, 2025, and reflects achievement of adjusted diluted earnings per share of $45.02, which exceeded the target performance level adjusted diluted earnings per share of $44.32. In 2025, we granted PSUs under our twentieth LPP cycle (“LPP 20”) to each of our NEOs, which are expected to be settled in 2028 contingent upon the Company’s adjusted diluted earnings per share growth performance over the January 1, 2025 to December 31, 2027 performance period. Annual Incentive Compensation. Annual incentives paid to our NEOs reflected our application of the incentive pool funding framework adopted by the Organization and Compensation Committee (the “Compensation Committee”), as well as the committee’s evaluation of each NEO’s contributions to our business and financial results, delivery of key strategic initiatives, and personal leadership qualities. The incentive pool funding determination included both a pre-established formulaic financial component (80% weighted), based on comparison of current year adjusted operating income results against the prior year, and a non-formulaic People & Culture component (20% weighted), based on Company’s progress across four areas: wellbeing, belonging, engagement, and retention. Once determined, annual incentives to our NEOs (other than Mr. Case) were paid 65% in cash and 35% in the form of time-vested restricted share units, which provides value to our executives that is tied to the long-term performance of the Company. Mr. Case’s annual incentive was paid 65% in the form of cash and 35% in the form of performance share units under our twenty-first LPP cycle, as a further tie to the long-term performance of the Company. Annual incentives for 2025 were awarded to our NEOs in early 2026 following the Company’s achievement of adjusted operating income of $5,563 million. The annual incentive awards are described in more detail in the section captioned “Annual Incentive Awards Under Our Shareholder-Approved Plan” below. Compensation-Related Best Practices Our compensation philosophy and related governance features are complemented by several policies and practices designed to align our executive compensation program with the long-term interests of our shareholders, including the following:

  8. Director Nominee Composition

    | Robust share ownership guidelines for senior executives and directors | Clawback and forfeiture provisions in the event of fraud or a material violation of Company policies | Annual say-on-pay vote for shareholders | | Robust annual risk assessment of compensation structure, policies and practices | People & Culture performance metric for determining executive annual incentives | Prohibition on hedging transactions by all employees and directors; prohibition on pledging by executive officers and directors | | Pay for performance philosophy weighted towards variable at-risk performance-based compensation | No dividends or dividend equivalents paid on unvested equity awards | Effective balance between differentiated short-term and long- term performance factors and incentives |

  9. Director Nominee Composition

    Proposal 1 — Resolutions Regarding the Election of Directors

  10. Director Nominee Composition

    | | The Board of Directors unanimously recommends that shareholders vote “FOR” each nominee to serve as director. |

  11. Director Nominee Composition

    What am I voting on? The current members of the Board are standing for election, in each case to serve until our 2027 annual general meeting. The 13 directors who are standing for election are named below. The Governance/Nominating Committee of the Board (the “Governance/Nominating Committee”) has recommended to the Board that each director be nominated. With respect to Mr. Case, his employment agreement provides that he will be nominated for election as a director at each annual general meeting of shareholders during the period of his employment. All nominees for director have consented to being named in this proxy statement and have agreed to serve as directors if re-elected. We have no reason to believe that any of the nominees will not be available to serve as a director. However, if any nominee should become unavailable to serve for any reason, the proxies may be voted for such substitute nominees as may be designated by the Board, or the Board may reduce its size. The term of each director expires at the next annual general meeting of shareholders, and each director will continue in office until the election of his or her respective successor or until his or her earlier resignation or removal in accordance with the Company’s articles of association (the “Articles”) or the Irish Companies Act 2014, as amended (the “Irish Companies Act”). Consistent with the terms of the Articles, the Board currently is authorized to have up to 21 directors, and the number of directors was most recently set by the Board at 13. Proxies cannot be voted for a greater number of persons than the number of nominees named. Our governing documents provide that a director nominee be elected by a majority of votes cast in an uncontested election. If an incumbent director nominee fails to receive a majority of the votes cast in an election that is not a contested election, the director must tender a resignation, and the Board shall decide, through a process managed by the Governance/Nominating Committee, whether to accept or reject the resignation or whether other action shall be taken. In reaching its decision, the Governance/Nominating Committee and the Board may consider any factors they deem appropriate and relevant. The Board will act on the recommendation of the Governance/Nominating Committee at its next regularly scheduled meeting and will promptly disclose the rationale for its decision in a Form 8-K furnished to the Securities and Exchange Commission (the "SEC"). A shareholder may: (i) vote for the election of a nominee; (ii) vote against the election of a nominee; or (iii) abstain from voting on a nominee. Unless an executed proxy contains instructions to the contrary, the proxy will be voted “FOR” the re-election of each nominee named on the following pages. The form of shareholder resolution for this proposal is below:

  12. Director Nominee Composition

    | RESOLVED THAT, the following individuals be, and each hereby is, by way of separate ordinary resolution, re-elected to serve as director for a term expiring at the next annual general meeting of shareholders and until the election of his or her respective successor or until his or her earlier removal or resignation pursuant to the Articles or the Irish Companies Act: | | | Lester B. Knight Jose Antonio Álvarez Jin-Yong Cai Jeffrey C. Campbell Gregory C. Case Cheryl A. Francis Jo Ann Jenkins | Adriana Karaboutis Richard C. Notebaert Gloria Santona Sarah E. Smith Byron O. Spruell James G. Stavridis |

  13. Director Nominee Composition

    Aon values a number of attributes and criteria when identifying nominees to serve as a director, including professional background, expertise, reputation for integrity, business, financial and management experience, leadership capabilities, international experience and perspectives, and a variety of backgrounds, skills, experiences and other demographics, as well as the ability to commit sufficient time and attention to the activities of the Board. We believe all of the nominees have a strong reputation for integrity, demonstrate effective leadership, and work collaboratively to contribute meaningfully to the Board and management and deliver long-term value for our shareholders and other stakeholders. Biographical information about each nominee and the experience, qualifications, attributes, and skills considered by our Governance/Nominating Committee and the Board in determining that each nominee should serve as a director appears below. Director Nominee Bios

  14. Director Nominee Composition

    | Committees: • Executive Committee (Chair) • Governance/Nominating Committee (Chair) • People & Wellbeing Sub- Committee Director Since: 1999 Age: 67 | Lester B. Knight • Founding Partner of RoundTable Healthcare Partners and the former Vice Chairman and director of Cardinal Health, Inc., a diversified healthcare service company. • First appointed Non-executive Chairman of the Board of Directors of Aon in August 2008. • Chairman of the Board and Chief Executive Officer of Allegiance Corporation (1996 to 1999). • Held executive and leadership roles with Baxter International, Inc. (1981 to 1996), including as Corporate Vice President (from 1990), Executive Vice President (from 1992) and as a director (from 1995). • Life director of NorthShore University Health System and Junior Achievement of Chicago, a life Trustee of Northwestern University and a member of the Civic Committee of The Commercial Club of Chicago. Skills & Qualifications: Mr. Knight’s experience as the founder of a private equity firm focused on investing in the healthcare industry, his executive background at several leading healthcare companies, and his financial and investment expertise provide the Board with global perspective, executive leadership and oversight experience. In addition, his role in chairing our Governance/Nominating Committee and his previous leadership and Board experience at other public companies position him to effectively lead the Board and promote a robust, deliberative decision-making process among independent directors. Mr. Knight also provides valuable perspectives with his broad experience in corporate governance, strategic transactions, business transformation and growth, and risk oversight. | | Committees: • Executive Committee • People & Wellbeing Sub- Committee Director Since: 2005 Age: 63 | Gregory C. Case • Chief Executive Officer and a director of Aon since April 2005, and President since March 2025. • Prior to joining Aon, held leadership roles with McKinsey & Company, the global management consulting firm, for 17 years, where he served on the governing Shareholders’ Council and as head of the Global Insurance and Financial Services Practice. • Prior to McKinsey, was with the investment banking firm of Piper, Jaffray and Hopwood and the Federal Reserve Bank of Kansas City. • Former director of Discover Financial Services. Skills & Qualifications: As President and Chief Executive Officer of Aon, Mr. Case brings to the Board his day-to-day experiences leading Aon’s colleagues serving clients across Commercial Risk, Reinsurance, Health and Wealth solution lines, and his intimate knowledge of Aon’s business, strategy, and operations. Mr. Case’s background as a management consultant, including in the global insurance and financial services areas, brings critical industry and business development knowledge to the Board. His extensive and specific knowledge of Aon and its global businesses provides our Board with a unique and valuable understanding of the Company’s priorities for our clients, colleagues and shareholders, and enables him to keep the Board apprised of the most significant developments impacting the Company and to guide the Board’s discussion and review of the Company’s strategy. Aon has benefited from continuity of Mr. Case's exceptional leadership, including his strategic guidance and long-term direction to drive continued growth and align the organization around sustained, high quality performance. |

  15. Director Nominee Composition

    | Committees: • Audit Committee • Organization and Compensation Committee Director Since: 2024 Age: 66 Current Public Company Directorship: • Banco Santander, S.A. | Jose Antonio Álvarez • Vice Chair and Non-executive director of Banco Santander, S.A., a Spanish multinational financial services company (since 2022). • Chief Executive Officer of Santander (2015 to 2022). • Joined Santander in 2002 and served as Executive Vice President and Chief Financial Officer (2004 to 2014). • Former member of the supervisory boards of Santander Consumer Bank AG, Santander Consumer Holding GmbH and Santander Bank Polska, S.A., and former director of SAM Investments Holdings Limited, Santander Consumer Finance, S.A. and Santander Holdings USA, Inc. • Former board member of Bolsas y Mercados Españoles, S.A. and Banco Santander (Brasil) S.A. Skills & Qualifications: Mr. Álvarez’s experience as former chief executive officer, and previously chief financial officer, of a multinational financial services company provides the Board with deep knowledge and expertise in international finance, and unique insights into emerging and global markets and investments. In addition, as a member or prior member of the boards of directors of several international companies that invest globally, Mr. Álvarez brings substantive expertise in business strategy in international markets, as well as business transformation, regulatory compliance, information technology, and risk management. Mr. Álvarez’s extensive financial background and experience has led the Board to determine that he is an “audit committee financial expert” as defined by the Securities and Exchange Commission (the “SEC”). |

  16. Director Nominee Composition

    | Committees: • Finance Committee (Chair) • Executive Committee • Organization and Compensation Committee Director Since: 2016 Age: 66 | Jin-Yong Cai • Partner, Global Infrastructure Partners, a global private equity investment firm and wholly-owned subsidiary of BlackRock, Inc. • Former Partner, TPG Capital, L.P., a global private equity investment firm. • Chief Executive Officer of the International Finance Corporation (2012 to 2016), a member of the World Bank Group and the largest global development institution focused on private sector development. • Nearly two decades of experience in the financial services industry after beginning his career at the World Bank Group, including 12 years with Goldman Sachs Group, as a Partner and its top executive in China. • Former director of PetroChina Company Limited and Syngenta Group. Skills & Qualifications: Mr. Cai’s experience in global finance and international business, particularly in the Asia-Pacific region, enhances the Board’s global perspectives and provides unique insights into global markets. Mr. Cai’s increased level of financial literacy and extensive background with international finance and global management, including areas relating to investment banking and private equity, provide valuable perspective and knowledge relating to financial risk and risks related to the Company’s international activities and growth strategies. |

  17. Director Nominee Composition

    | Committees: • Audit Committee (Chair) • Executive Committee • Organization and Compensation Committee Director Since: 2018 Age: 65 Current Public Company Directorships: • Hexcel Corporation • Marathon Petroleum Corporation | Jeffrey C. Campbell • Chief Financial Officer of American Express Company, a financial services company (July 2013 to August 2023); Vice Chairman of American Express Company (April 2021 to March 2024). • Executive Vice President and Chief Financial Officer of McKesson Corporation, a leading healthcare services, information technology and distribution company (2004 to 2013). • Previously spent 13 years at AMR Corporation and its principal subsidiary, American Airlines, ultimately becoming its Chief Financial Officer (in 2002). • Lead Director and member of the Audit Committee of Hexcel Corporation, and director and Chair of the Audit Committee of Marathon Petroleum Corporation. • Board member of The Julliard School; Former Board member of the Lincoln Center for the Performing Arts and former Chair of the Lincoln Center Corporate Fund. Skills & Qualifications: Having served as chief financial officer of three multinational, publicly traded companies, Mr. Campbell adds financial expertise and risk management leadership to the Board. His significant business experience, deep financial acumen and leadership in the development of broad-based talent provide the Board and its committees with valuable, broad ranging management perspective. He also brings substantial experience in the areas of compliance, risk oversight, corporate finance, strategy, corporate governance and corporate social responsibility, as well as knowledge and experience relating to the financial services sector. This experience has also led the Board to determine that Mr. Campbell is an “audit committee financial expert” as defined by the SEC. |

  18. Director Nominee Composition

    | Committees: • People & Wellbeing Sub- Committee (Chair) • Finance Committee • Governance/Nominating Committee • Organization and Compensation Committee Director Since: 2010 Age: 72 Current Public Company Directorships: • HNI Corporation • Morningstar, Inc. | Cheryl A. Francis • Executive Vice President and Chief Financial Officer of R.R. Donnelley & Sons Co. (1995 to 2000), a publicly traded print media company. • Co-Chair, Corporate Leadership Center (since 2008) and Business Consultant (since 2000). Previously Vice Chairman, Corporate Leadership Center (2002 to 2008). • Chief Financial Officer of FMC Gold (1987 to 1991), and Treasurer of FMC Corporation (1993 to 1995). • Director of HNI Corporation, a leading provider of workplace furnishings, and Morningstar, Inc., a global provider of investment insights. • Former director of Hewitt Associates, Inc. from 2002 until Aon's acquisition of Hewitt Associates, Inc. in 2010. Skills & Qualifications: Ms. Francis’s background as a chief financial officer of a large publicly traded company provides the Board with an increased level of financial literacy, as well as regulatory and business oversight. In addition, her role as a Board member of other public companies provides valuable perspective on matters of risk oversight, strategy, corporate governance, and human capital management. As Co-Founder of the Corporate Leadership Center’s CEO Perspectives and Leading Women Executives, Ms. Francis is a leading voice on inclusion and leadership development and brings focus to our work to promote corporate social responsibility. |

  19. Director Nominee Composition

    | Committees: • Audit Committee Director Since: 2025 Age: 68 Current Public Company Directorships: • Avnet, Inc. • General Mills, Inc. | Jo Ann Jenkins • Chief Executive Officer of AARP, a nonprofit, nonpartisan membership organization dedicated to issues affecting Americans over the age of 50 (2014 to 2024). • Chief Operating Officer of AARP (2013 to 2014) and President, AARP Foundation (2010 to 2013). • Former Chief Operating Officer and Chief of Staff at the Library of Congress. • Previously held a variety of senior roles at the U.S. Department of Agriculture, the U.S. Department of Transportation, and the U.S. Department of Housing and Urban Development. • Director of Avnet, Inc., a global electronic components distributor, and General Mills, Inc., a multinational food company. Skills & Qualifications: As the former Chief Executive Officer of AARP, Ms. Jenkins brings to the Board a deep understanding of strategic management, global policy leadership, and oversight from her experiences leading and transforming one of the largest nonprofit organizations in the United States. Ms. Jenkins' background and experience contribute valuable insights to the Board on public policy, government affairs, and community relations matters based on her senior leadership positions at the Library of Congress, U.S. Department of Agriculture, U.S. Department of Transportation, and U.S. Department of Housing and Urban Development. Her public and private board service and advisory experiences deepen the Board’s overall governance expertise. |

  20. Director Nominee Composition

    | Committees: • Audit Committee • Governance/Nominating Committee Director Since: 2022 Age: 63 Current Public Company Directorships: • Perrigo Company plc • Autoliv Inc. • Savills plc | Adriana Karaboutis • Chief Information and Digital Officer of National Grid PLC (2017 to 2023), one of the world’s largest public utility companies focused on transmitting and distributing electricity and gas in the UK and northeast US. • Executive Vice President, Technology, Business Solutions and Corporate Affairs at Biogen Inc., a global biotechnology company (September 2014 to March 2017). • Vice President and Global Chief Information Officer of Dell, Inc., a global technology company (March 2010 to September 2014). Previously spent over 20 years with General Motors Company and Ford Motor Company in various international leadership positions, including global production planning, computer integrated manufacturing, and supply chain operations. • Director and member of the Audit Committee of Perrigo Company plc, a global over-the-counter consumer goods and self-care company, director and member of the Audit, Risk, and Compliance Committee of Autoliv Inc., a global supplier of automotive safety systems, and director of Savills plc, a global real estate services company. • Former director of Aspen Technology, Advance Auto Parts and Blue Cross Blue Shield of Massachusetts. Skills & Qualifications: Ms. Karaboutis’ background as a chief information officer for both a public utility company and a global technology company provides the Board with valuable insight and experience in technology, cybersecurity, data privacy, and data security matters, as well as business operations and continuity. Her experience in developing and delivering digital solutions, advancing data science capabilities, overseeing innovative technology, and leading global business operations further strengthens the Board’s perspective on innovation-driven strategies and related strategic and risk oversight matters. In addition, Ms. Karaboutis' service as a current and former director of multiple public companies brings a global viewpoint and deep experience in risk oversight, corporate governance, and executive management. |

  21. Director Nominee Composition

    | Committees: • Executive Committee • Organization and Compensation Committee • Finance Committee • Governance/Nominating Committee • People & Wellbeing Sub- Committee Director Since: 1998 Age: 78 | Richard C. Notebaert • Chairman and Chief Executive Officer of Qwest Communications International Inc., a global telecommunications system company (2002 to 2007). • President and Chief Executive Officer of Tellabs, Inc., a company designing and marketing equipment and services to communications-service providers worldwide (August 2000 to June 2002), and director of Tellabs (April 2000 to June 2002). • Chairman and Chief Executive Officer of Ameritech Corporation, a full-service communications company (1994 to 1999). Previously served in significant positions within the Ameritech organization before his election as Vice Chairman in January 1993, President and Chief Operating Officer in June 1993, and President and Chief Executive Officer in January 1994. • Trustee Emeritus of the Board of Trustees of the University of Notre Dame. • Former director of American Electric Power Company and Cardinal Health, Inc., and former Chairman of the Board of Trustees of the University of Notre Dame. Skills & Qualifications: Mr. Notebaert’s background as a chairman and chief executive officer of several large international communications companies provides the Board with substantial management expertise, including in the areas of global operations, technology and innovation, and strategic planning. In addition, Mr. Notebaert’s executive and board leadership experience provides valuable perspectives on matters of corporate governance, human capital management, executive compensation, and risk oversight. |

  22. Director Nominee Composition

    | Committees: • Audit Committee • Governance/Nominating Committee • People & Wellbeing Sub- Committee Director Since: 2004 Age: 75 | Gloria Santona • Of Counsel at Baker McKenzie, an international law firm (2018 to 2022). • Executive Vice President, General Counsel and Secretary of McDonald’s Corporation (2001 to 2017). • Held positions of increasing responsibility at McDonald's, including U.S. General Counsel (December 1999 to June 2001) and corporate General Counsel (2001 to 2017). • Former Trustee of Rush University Medical Center, the Chicago Zoological Society and the Chicago Symphony Orchestra, and former board member of The Chicago Network, the Chicago Food Depository, the National Immigrant Justice Center, the American Society of Corporate Secretaries, the Association of Corporate Counsel and the Minority Corporate Counsel Association. • Former member of the Audit Committee and the Governance Committee of the Rush System for Health. Skills & Qualifications: Ms. Santona’s legal background, including her experience serving as a general counsel and secretary of a large international corporation, brings critical perspective to the Board and enhances the Board’s global risk management and oversight capabilities. Ms. Santona’s diverse legal background contributes corporate governance, legal, regulatory and compliance expertise, and further brings valuable perspective on long-term growth strategy planning. Under Ms. Santona’s leadership, McDonald’s legal department won numerous awards for its commitment to inclusivity and pro bono, and Ms. Santona’s service and leadership experience at non-profit organizations deepens the Board’s expertise on human capital management and social and governance priorities. |

  23. Director Nominee Composition

    | Committees: • Finance Committee • People & Wellbeing Sub- Committee Director Since: 2023 Age: 67 Current Public Company Directorships: • Nuveen Churchill Private Capital Income Fund • Klarna Group plc • Via Transportation, Inc. | Sarah E. Smith • Former member of the Management Committee of The Goldman Sachs Group, Inc., a global investment banking, securities and investment management firm. Ms. Smith joined Goldman Sachs in 1996 and was named Managing Director in 1998 and Partner in 2002. Served as Controller and Chief Accounting Officer of the firm until 2017, and subsequently as Chief Compliance Officer (2017 to 2020) and Senior Advisor to Goldman Sachs (2020 to 2021). • Previously worked in the National and Audit practices of KPMG in both London and New York and held several finance positions at Bristol-Myers Squibb. • Former member of the Board of Trustees of the Financial Accounting Foundation; attended City of London University (Dip. Acc) and is a Fellow of the Institute of Chartered Accountants in England and Wales. • Trustee of Nuveen Churchill Private Capital Income Fund, director and Chair of the Audit Committee of Klarna Group plc, a global digital bank and flexible payments provider, and director of Via Transportation, Inc., a technology firm that transforms transportation systems into highly efficient digital networks. Skills & Qualifications: Ms. Smith’s background as a chief accounting officer and chief compliance officer of a global investment banking firm provides the Board with an increased level of financial literacy and enhances the Board’s expertise in the oversight of risk management and compliance. In addition, Ms. Smith’s experience in the investment banking and asset management industries brings valuable insight to the Company’s business strategy and operations in professional and financial services. |

  24. Director Nominee Composition

    | Committees: • Organization and Compensation Committee (Chair) • Audit Committee • People & Wellbeing Sub- Committee Director Since: 2020 Age: 61 | Byron O. Spruell • President of League Operations of the National Basketball Association (since August 2016), a professional basketball league. • Previously spent 20 years at Deloitte LLP, most recently as its Vice Chairman, Central Region Marketplace Leader and Chicago Managing Principal. • Trustee and former Chair of the Audit Committee of the University of Notre Dame. • Board member of the Museum of Science and Industry, Metropolitan Family Services in Chicago and the Jackie Robinson Foundation and former board member of several nonprofit organizations. Skills & Qualifications: Mr. Spruell has extensive executive leadership experience, with a focus on strategy, business continuity, and application of analytics and innovation. His background in a professional services firm and as a current executive at the National Basketball Association also provides the Board with valuable experience in operations management, human capital management, and talent development, as well as colleague health and wellness. Mr. Spruell’s experiences at Deloitte LLP and as Chair of the Audit Committee of the University of Notre Dame’s Board of Trustees further elevates the Board’s financial and accounting literacy. Additionally, Mr. Spruell’s service on nonprofit boards enhances the Board’s perspectives on organizational strategy, community impact, and stakeholder engagement. |

  25. Director Nominee Composition

    | Committees: • Finance Committee Director Since: 2024 Age: 70 Current Public Company Directorship: • Fortinet, Inc. | Admiral James G. Stavridis • Partner and Vice Chair, Global Affairs of Carlyle Group Inc., a global investment firm (since 2018). • Former member of the United States Navy, serving from 1976 to 2013, and rising to the rank of 4-star Admiral in 2009. Admiral Stavridis' commands included four years as the 16th Supreme Allied Commander with The North Atlantic Treaty Organization (NATO), where he oversaw operations in Afghanistan, Libya, Syria, the Balkans, and counter piracy off the coast of Africa, as well as three years commanding the U.S. Southern Command, with responsibility for all military operations throughout Latin America. • Former Dean of The Fletcher School of Law and Diplomacy at Tufts University. • Director of Fortinet, Inc., a cybersecurity company; former director of American Water Works Company, Inc., a publicly traded water utility company, and Neuberger Berman Funds. • Chair of the Board of Trustees of The Rockefeller Foundation, and board member of several private companies and non-profit organizations. Skills & Qualifications: Admiral Stavridis brings extensive government and leadership experience as a result of his military service, providing the Board with global perspective and expertise in the areas of strategic planning and investments, leadership, global operations, and technology. As an internationally recognized strategic and global affairs expert, he brings to the Board substantial knowledge and insights in the areas of regulatory compliance, risk management, and cybersecurity matters. In addition, Admiral Stavridis’s extensive experience in private sector and government leadership positions enhances the Board’s perspectives in conducting business in diverse geopolitical environments. His longstanding commitments to government and educational organizations contribute valuable insights to the Board on corporate social responsibility and human capital management matters. |

  26. Director Nominee Composition

    Corporate Governance Aon is committed to effective corporate governance, which we believe helps sustain our success and build long-term value for our shareholders and other stakeholders. Aon’s Corporate Governance Guidelines provide the framework for our system of corporate governance, which, together with our committee charters and Code of Business Conduct, set forth standards for employees, officers and directors. The Board and its committees provide oversight of Aon’s overall performance, strategic direction, and executive management team performance, including management of the Company’s top risks and mitigation plans. The Board also reviews major initiatives and transactions and advises on key financial and business matters. The charter of each standing committee and sub-committee, the Corporate Governance Guidelines, and the Code of Business Conduct are available on the corporate governance section of our website at http://www.aon.com/about-aon/corporate-governance/corporate-governance.jsp. For more information about our Board’s and management’s oversight of risks please see “Board Role in Risk Oversight” below.

  27. Director Nominee Composition

    | Corporate Governance Best Practices | | | | Board Independence. All of our directors are independent, with the exception of our Chief Executive Officer. | | | Independent Chair. We have had an independent chair Board leadership structure since 2008. | | | Active Board Refreshment. We have a strong, refreshed Board with deep, relevant experience as well as a mix of tenures and personal backgrounds. Five new independent directors have been nominated in the last six years and two Board Committees are led by newly appointed chairs. | | | People & Wellbeing Sub-Committee. The People & Wellbeing Sub-Committee of the Governance/Nominating Committee helps to ensure focused evaluation, oversight, and management of Aon’s engagement and wellbeing strategies and initiatives. | | | Annual Elections with Majority Voting. Directors are elected annually by a majority of votes cast in an uncontested election. | | | Robust Year-Round Shareholder Engagement Program. Aon proactively conducts shareholder outreach throughout the year to gather feedback and better understand shareholder perspectives on long-term strategy, governance practices, executive compensation, and other business priorities, including corporate sustainability and human capital matters. | | | Oversight of Director Commitments. Our Governance/Nominating Committee regularly reviews director commitments, and our Corporate Governance Guidelines limit a director’s service on outside boards. | | | Annual Board, Committee and Director Peer Evaluations. Aon’s directors participate annually in comprehensive evaluations on Board effectiveness, committee performance and individual peer assessment, facilitated by an experienced external third party. | | | Shareholder Right to Call a Special Meeting. Our shareholders owning 10% of our shares may request that the Company call an extraordinary general meeting, in accordance with the requirements of the Irish Companies Act. | | | Share Ownership Guidelines. We maintain robust share ownership guidelines for our directors and senior executives. | | | Executive Sessions. Our independent directors meet regularly in executive sessions. | | | Director Onboarding and Education. Our directors receive a comprehensive onboarding upon joining the Board and ongoing education relevant to our business and strategy. | | | Prohibitions on Hedging and Pledging Company Shares. Our Board has adopted an insider trading policy which, among other things, specifically prohibits all employees and directors from engaging in short sales, publicly traded options, puts and calls, forward sale contracts, and other swap, hedging and derivative transactions relating to Aon securities. The policy also specifically prohibits our executive officers and directors from holding Aon securities in margin accounts or pledging them as collateral for a loan. |

  28. Director Nominee Composition

    Board Leadership Structure Our Board leadership structure consists of an independent, non-executive Chairman of the Board, a separate Chief Executive Officer, and independent committee chairs. Aon's Corporate Governance Guidelines provide that the positions of Chairman of the Board and Chief Executive Officer may be held by the same or different individuals. These Guidelines give the Board the flexibility to periodically evaluate and adopt the leadership structure that best serves the interests of the Company and its shareholders, considering the Company's evolving needs and circumstances. Mr. Knight serves as our Non-Executive Chair. Mr. Knight's Board service and leadership as Chair of the Governance/Nominating Committee has provided him with deep institutional knowledge and a strong understanding of our governance framework, and equips him with the skills necessary to effectively lead our Board. In his role, Mr. Knight acts as liaison between the Board and management, sets the agendas for, and presides over, the Board meetings and chairs executive sessions of the non-management directors. Mr. Case, as Chief Executive Officer, also serves as a member of the Board and contributes extensive expertise relating to the Company's strategy and businesses, industry knowledge and a deep understanding of our stakeholder relationships. His insights into the most significant developments facing the Company are instrumental in guiding the Board's discussion and aligning its strategic oversight with the Company's long-term objectives. The Board believes the separation of the positions of Chief Executive Officer and Chair is the most appropriate structure at this time to best serve the Company and its shareholders, as it allows our Chief Executive Officer to focus on the management of the Company and the Chair to ensure that the Board is focused on its oversight responsibilities, including independent oversight of management. The structure also facilitates robust communication between management and the Board and provides effective oversight by independent directors, including oversight of risks. Board Role in Risk Oversight Risk is inherent and evolving in every business, and how well a business manages risk can ultimately determine its success. At Aon, risk is actively managed through our enterprise risk management (“ERM”) program, which covers the range of material risks to Aon, including strategic, operational, financial, compliance, human capital, technology, security and corporate sustainability risks. The Board oversees Aon’s enterprise risk management program and allocates certain oversight responsibilities to its committees and any sub-committee, as appropriate. Each committee reports regularly to the Board on risk matters under its purview. The Board and its committees regularly review our risk management policies, processes and controls. The Board has delegated to the Audit Committee the primary responsibility for the oversight of the Company’s ERM program. Management carries out the daily processes, controls, and practices of our risk management program, many of which are embedded throughout our operations. Through our ERM process, management identifies, assesses, prioritizes, monitors, and develops mitigation plans for Aon’s top risks. The Board believes that establishing the right tone at the top and maintaining full and open communication between management and the Board are essential for effective risk management and oversight. As such, the Board and its committees regularly review and discuss with management the Company’s risk landscape, ERM governance, and progress on key risk management priorities, including emerging risks associated with growth initiatives and changing geopolitical and macroeconomic conditions. Throughout the year, the Board and the committees review the Company’s management of risk, including but not limited to the areas of cybersecurity and data security, data privacy, business continuity, compliance with government regulations, errors & omissions claims, financial performance, liquidity, taxes, mergers and acquisitions, corporate sustainability, and human capital management. In addition, members of senior management attend Board and committee meetings (including private sessions with independent directors when invited) to address any questions or concerns raised by the Board related to risk management and any other matters. Cybersecurity, Data Security, and Data Privacy Risk Management and Board Oversight Cybersecurity, data security, data privacy and data protection matters are an important focus of our Board’s oversight of risk. The Audit Committee has primary responsibility for the oversight of cybersecurity and data privacy risks and engages in regular discussion with management regarding cybersecurity and data privacy risk mitigation and incident management, including risks arising from the use of artificial intelligence ("AI"). The Company’s management, including the Chief Privacy and Data Trust Officer and the Chief Information Security Officer, regularly presents (no less than twice annually) to the Audit Committee of the Board regarding cybersecurity, data security, data privacy and data protection matters. Aon’s cybersecurity, data security, data privacy and data protection programs are designed to protect the personal and confidential data of our clients and our colleagues. Aon engages in a risk-based approach to adopting and implementing appropriate technical, organizational, administrative, and physical safeguards for cybersecurity. One key component to safeguard against risks facing Aon’s technology and security is Aon’s ERM program, as discussed above, which includes management’s identification, assessment, prioritization, and mitigation of cybersecurity risks. In addition, the Company has embedded responsible AI principles in its Code of Business Conduct and established a cross-functional AI working group which is focused on enabling innovation in the development and use of AI in our solutions as well as our internal operations, while mitigating risks. Our AI governance program assesses and prioritizes AI opportunities, solutions and risks across the firm, and the Company’s management provides relevant updates regarding such matters to the Board, including with respect to the evolving AI security governance landscape. In addition, employees across the Company receive periodic training and education on cybersecurity-related topics and governance matters. Aon has established a Global Privacy and Data Trust Office led by a Chief Privacy and Data Trust Officer and comprised of full-time privacy professionals located around the globe, responsible for implementing Aon’s data privacy program, and designing and developing data privacy compliance solutions. In addition, Aon maintains a Global Cybersecurity Services ("GCS") organization, led by our Chief Information Security Officer, with dedicated cybersecurity personnel responsible for protecting Aon’s information and information systems. Refer to Part I, Item 1C of Aon’s Annual Report on Form 10-K for the year ended December 31, 2025, for further information regarding Aon’s cybersecurity and risk management. Oversight of Corporate Sustainability Risks and Opportunities Our Board and management recognize that the full spectrum of corporate sustainability, including related risks, continues to evolve in significance to our business. As a result, oversight of corporate sustainability risks is an ongoing and dynamic commitment. Under Aon’s Corporate Governance Guidelines, the full Board oversees the Company’s corporate sustainability risks and opportunities, as well as related strategies, goals, objectives, and performance. The Board may from time-to-time delegate certain aspects of its corporate sustainability and related risk oversight responsibilities to one or more of its committees or sub-committees, which report on such matters to the full Board.

  29. Director Nominee Composition

    The Board reviews Aon’s corporate sustainability and climate strategy and, more broadly, the Board (including through its committees) oversees the Company’s corporate sustainability risks and opportunities, including those relating to human capital management, governance, climate, executive compensation, and colleague engagement and wellbeing. People-related risks, including colleague satisfaction and engagement survey results, pay equity, colleague wellbeing, succession planning, employment law matters and conduct and ethics matters, are regularly discussed, together with progress against Aon’s engagement and wellbeing strategy and initiatives. Management has responsibility for the governance and day-to-day execution of our corporate sustainability strategy, led by Aon's Corporate Sustainability Steering Committee (the "CS SteerCo"). The CS SteerCo, which is comprised of Aon executives, develops and executes our corporate sustainability strategy, policies and programs. The Board regularly reviews and oversees our corporate sustainability strategy, program and goals. The CS SteerCo reports periodically, and at least annually, to the Board in support of the Board’s oversight function of the Company’s corporate sustainability risks, opportunities, strategies, goals and objectives, and performance. Additional information regarding the purpose, governance, responsibilities and duties of the CS SteerCo, is available in our Impact Report, which can be found on the Company’s website, www.aon.com. The information contained in the Aon Impact Report or elsewhere on the Company’s website is not incorporated by reference into, and does not form part of, this proxy statement. Director Independence The Board has established Corporate Governance Guidelines which require that a majority of directors meet the independence requirements of the New York Stock Exchange (the “NYSE”). The Corporate Governance Guidelines further provide that each of the Audit Committee, Governance/Nominating Committee and Compensation Committee be composed entirely of independent directors. The Board has affirmatively determined that each nominee for director other than Mr. Case is independent. Mr. Case is considered a management director because of his position as our President and Chief Executive Officer. In addition, the Board has affirmatively determined that Fulvio Conti, who retired as a director effective as of June 27, 2025, was independent during the time he served on the Board. In determining that each of the non-management directors is independent, the Board also considered the following relationships that it deemed were immaterial to such director’s independence: With respect to Mr. Knight, Mr. Cai, Mr. Spruell, and Admiral Stavridis, the Board considered that, in the ordinary course of business, Aon has sold services to, or received services from, a company or other entity at which the director is (or during 2025 was) an employee and the amount that we received from or paid to the entity in any of the previous three fiscal years was below the greater of $1 million or two percent (2%) of that entity’s annual revenue; and With respect to Mr. Knight, Ms. Francis, Mr. Notebaert, and Mr. Spruell, the Board considered that Aon or certain of its affiliates made charitable contributions in 2025 to organizations in which the director or the director’s spouse was an officer, director, or trustee. In each case, the amount that we contributed was below the greater of $1 million or two percent (2%) of that organization’s consolidated gross revenue. Board of Directors and Committees The Board met six times in 2025. All nominees for director who served as a director in 2025 attended at least 75% of the total meetings of the Board and the standing committees and sub-committees on which they served during the period for which they served. In accordance with NYSE rules and the Corporate Governance Guidelines, non-management directors meet regularly in executive session without management. Mr. Knight, the Non-Executive Chair, chairs these executive sessions. The Board has five standing committees: the Executive Committee, the Audit Committee, the Finance Committee, the Governance/Nominating Committee and the Compensation Committee. The Board has also established the People & Wellbeing Sub-Committee as a standing sub-committee of the Governance/Nominating Committee. As part of our ongoing commitment to Board and committee refreshment, the Board regularly reviews committee leadership and membership rotation. In 2025, Mr. Spruell was appointed chair of the Compensation Committee and Mr. Cai was appointed chair of the Finance Committee. Executive Committee When the Board is not in session, the Executive Committee is empowered to exercise the power and authority in the management of the business and affairs of Aon as would be exercised by the Board, subject to certain exceptions. The current members of the Executive Committee are Lester B. Knight, Gregory C. Case, Jin-Yong Cai, Jeffrey C. Campbell, Richard C. Notebaert and Byron O. Spruell. Audit Committee The Company has a separately designated standing Audit Committee established in accordance with Section 3(a)(58)(A) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). The primary purposes of the Audit Committee are to assist the Board with the oversight of: • the integrity of Aon’s financial statements, financial reporting process and internal controls; • Aon’s compliance with legal and regulatory requirements and ethics programs; • the engagement of Aon’s independent auditor and its qualifications, independence and performance; • subject to the provisions of Irish law, the appointment and performance of Aon’s statutory auditor as required under Irish law; and • the performance of Aon’s internal audit function. The Audit Committee is authorized to retain outside counsel or other experts as it deems appropriate to carry out its duties and responsibilities. The Board has also delegated to the Audit Committee the primary responsibility for the oversight of the Company’s enterprise risk management. The Audit Committee reviews and discusses with management Aon’s guidelines and policies with respect to risk assessment and enterprise risk management, including the major financial risk exposures facing the Company and the steps management has taken to monitor and control such exposures. The Audit Committee also has primary responsibility for oversight of cybersecurity and data privacy risks and engages in regular discussion with management regarding cybersecurity and data privacy risk mitigation and incident management. The Audit Committee also has general oversight responsibility for the Company’s legal, regulatory, and ethics policies and programs and annually reviews the adequacy and appropriateness of those policies and programs, including Aon’s Code of Business Conduct. In addition, the Audit Committee periodically reviews with management any material correspondence with, or other action by, regulators or governmental agencies. The current members of the Audit Committee are Jeffrey C. Campbell, Jose Antonio Álvarez, Jo Ann Jenkins, Adriana Karaboutis, Gloria Santona, and Byron O. Spruell. In 2025, the Audit Committee met nine times. The Board has determined that each of the members of the Audit Committee is independent as defined by the rules of the NYSE and under the Company’s categorical independence standards, as well as Rule 10A-3 under the Exchange Act. In addition, as required by the rules of the NYSE, the Board has determined that all of the Audit Committee members are financially literate, and that Mr. Álvarez and Mr. Campbell are “audit committee financial experts” within the meaning of rules promulgated by the SEC. Additional information regarding the Audit Committee’s responsibilities may be found in this proxy statement in the section captioned “Report of the Audit Committee.”

  30. Director Nominee Composition

    Finance Committee The Finance Committee is primarily responsible for assisting the Board with monitoring and overseeing: • Aon’s balance sheet, including its long-term capital plan, capital structure and strategy for obtaining financial resources; • the Company’s proposed mergers, acquisitions, joint ventures and divestitures and the financial implications of such proposed transactions and, to the extent consistent with the Company’s policies and practices, make recommendations with respect to such proposed transactions and activities to the Board; • all long-term passive investments of the Company, other than such investments made pursuant to the Company’s co-investment policies approved by the Committee; • the financial, investment and actuarial policies and objectives of Aon’s U.S. tax-qualified defined benefit plans; • the investment performance of the Company’s non-U.S. benefit and retirement plans; • the Company’s corporate financing activities, including the issuance or guarantee of securities by the Company and its subsidiaries, and the offering terms of such securities and guarantees; • the Company’s treasury activities, including its liquidity risk, reviewing entry into and status of credit facilities and the use of derivatives and management of foreign exchange risk; and • Aon’s overall financial risk management program and major insurance programs, including any self-insurance programs. The current members of the Finance Committee are Jin-Yong Cai, Cheryl A. Francis, Richard C. Notebaert, Sarah E. Smith, and Admiral James G. Stavridis. Each member of the Finance Committee is independent as defined in the independence standards of the NYSE. The Finance Committee met four times during 2025. Governance/Nominating Committee The Governance/Nominating Committee oversees the risks associated with Aon’s overall governance and its primary responsibilities are to: • review with the Board the appropriate skills and criteria required of directors and nominees for director; • identify, consider and recommend individuals to fill new positions or vacancies on the Board; • recommend the slate of director nominees for each annual general meeting; • advise the Board with respect to the structure and operations of, as well as the composition and qualifications for membership on, the committees of the Board; • oversee the annual performance evaluation of the Board; • review the Corporate Governance Guidelines annually and make recommendations for changes to the Board; • review policies and procedures with respect to any transaction involving Aon and any related person and approve or ratify such transactions, as the Committee deems appropriate; and • establish share ownership guidelines for directors and executive officers and periodically review compliance. The current members of the Governance/Nominating Committee are Lester B. Knight, Cheryl A. Francis, Adriana Karaboutis, Richard C. Notebaert, and Gloria Santona. Each member of the Governance/Nominating Committee is independent as defined in the independence standards of the NYSE. The Governance/Nominating Committee met five times during 2025. People & Wellbeing Sub-Committee The People & Wellbeing Sub-Committee is a standing subcommittee of the Governance/Nominating Committee, and its primary responsibilities are to: • oversee the Company's engagement and wellbeing strategies and initiatives; • review the Company’s strategic business efforts relating to engagement and wellbeing; and • perform any other duties as directed by the Governance/Nominating Committee or the Board. The current members of the People & Wellbeing Sub-Committee are Cheryl A. Francis, Gregory C. Case, Lester B. Knight, Richard C. Notebaert, Gloria Santona, Sarah E. Smith, and Byron O. Spruell. The People & Wellbeing Sub-Committee met five times during 2025. Compensation Committee The Compensation Committee assists the Board in carrying out its overall responsibilities with regard to executive and director compensation, including oversight of the determination and administration of our compensation philosophy, policies, programs and plans for executive officers and non-management directors. In addition, among other matters, the Compensation Committee: • annually reviews and approves the compensation of Aon’s officers subject to Section 16 of the Securities Exchange Act of 1934 and other members of senior management as the Compensation Committee deems appropriate, and makes recommendations for consideration and approval by the independent members of the Board with respect to the compensation of the Chief Executive Officer; • directly approves the compensation of executive officers other than the Chief Executive Officer, including special hiring and severance arrangements; • reviews and makes recommendations to the independent directors, when necessary, with respect to the Company’s incentive compensation plans and equity-based compensation plans and exercises power and authority as may be permitted under those plans; • authorizes or approves the adoption, amendment or termination of the Company’s material employee benefit plans and programs and reviews and approves the appointment of fiduciaries with respect to the fiduciary committees of certain of the Company’s employee benefit plans; • reviews and makes recommendations to the Board concerning non-employee director compensation; and • reviews and discusses the compensation disclosures contained in the proxy statement. As part of these duties, the Compensation Committee reviews the risks associated with Aon’s compensation policies and practices, including a review of Aon’s risk assessment of its compensation policies and practices for its employees. In compliance with the committee charter, the Compensation Committee may establish subcommittees consisting of one or more members or other independent directors and may delegate to such subcommittees and management power and authority to carry out such duties as the Compensation Committee may delegate. The current members of the Compensation Committee are Byron O. Spruell, Jose Antonio Álvarez, Jin-Yong Cai, Jeffrey C. Campbell, Cheryl A. Francis, and Richard C. Notebaert. Each member of the Compensation Committee is independent as defined in the independence standards of the NYSE and is a non-employee director as defined in Rule 16b-3 promulgated under the Exchange Act. The Compensation Committee met seven times during 2025. Additional information regarding the Compensation Committee’s responsibilities may be found in this proxy statement in the sections captioned “Compensation Committee Report” and “Compensation Discussion and Analysis.” Other Corporate Governance Practices Board and Committee Evaluations

  31. Director Nominee Composition

    Our Board is committed to ongoing evaluation and continuous improvement. Each year, directors complete comprehensive evaluations that address overall Board effectiveness, committee performance and individual peer assessments. The Governance/Nominating Committee oversees the annual evaluation process, and the Board retains an outside party to review the completed evaluations. The full Board and each of the committees discuss their self-assessments in executive sessions at least annually. In addition, the Chair of the Governance/Nominating Committee conducts one-on-one discussions with each director to obtain his or her views on the effectiveness and performance of the Board and its committees. The Governance/Nominating Committee periodically reviews and refines the form and process for Board and Committee self-evaluations. Feedback regarding individual directors is shared with the Chair of the Governance/Nominating Committee, who meets with each independent director individually. Throughout the year, directors also have regular opportunities to provide input directly to the Chairman, committee chairs and management on meeting processes, materials and resources, agenda topics for Board and committee meetings, and strategy discussions. The Board believes that this robust evaluation process enhances its effectiveness, supports continuous improvement, and reinforces the Board's continued focus on Board refreshment and composition. Director Commitments The Governance/Nominating Committee considers each director’s and nominee’s time commitments, including those related to employment and other board service, to assess their capacity to fulfill Board responsibilities. Our Corporate Governance Guidelines provide that a director must notify the Board Chair prior to accepting any invitation to serve on another public company board, and that a director may not serve on the boards of more than three other public companies, in addition to service on the Company's Board, unless otherwise approved by the Governance/Nominating Committee. In addition, directors are required to offer to tender their resignation from the Board in the event of a substantial change in their principal occupation, subject to review and consideration by the Governance/Nominating Committee. Director Onboarding and Education Upon joining the Board, new directors participate in a comprehensive onboarding program covering Aon's business, strategy and governance. New directors also engage in introductory meetings with senior business and functional leaders to gain additional insight into the Company's operations and priorities. On an ongoing basis, directors receive presentations on a range of topics relevant to Board service and the Company's business and industry, delivered by senior management and external experts. The Board also receives periodic briefings and education on core concepts, emerging trends, and related risks and opportunities relevant to Aon's strategy and operations, as well as in areas such as information security and AI. Directors may also enroll in continuing education programs sponsored by third parties at the Company's expense. CEO and Senior Leadership Succession Planning The Board views CEO and senior leadership succession planning as a critical component of the Company's overall strategic planning process, helping to ensure continuity of leadership and effective execution of Aon's long-term objectives. Our Independent Board Chair oversees the CEO succession planning process. The full Board as well as the independent directors, at least annually, discuss CEO succession planning, including emergency succession plans and related processes. The Board also regularly reviews and discusses senior leadership succession planning and development to help ensure long-term organizational strength. Our Board reviews potential internal senior management candidates with our CEO and our Chief Administrative Officer, including the qualifications, experience, and development priorities for these individuals. Directors engage with potential CEO and senior management successors at Board and committee meetings, as well as in less formal settings, to personally assess potential candidates for these key roles. In addition, the Board periodically reviews the overall composition of senior management, including qualifications, tenure, and experience. Human Capital Management Aon’s Board recognizes that effective human capital management – including leadership development, senior leadership succession planning, and continuing to strengthen our talent pipeline – is essential to advancing our long‑term strategy, sustaining our performance, and attracting, developing, and retaining the talent necessary to serve clients and deliver long-term shareholder value. Oversight of human capital matters is integrated across the Board and its committees, reflecting the importance of talent, culture, and leadership to Aon’s success. For example, the Compensation Committee plays a central role in overseeing compensation and benefit programs that support Aon’s human capital objectives, including the design and administration of executive compensation, equity programs, and key benefit and wellbeing plans that apply to senior leaders and the broader workforce. In addition, the People & Wellbeing Sub‑Committee of the Governance/Nominating Committee provides focused oversight of colleague engagement and wellbeing initiatives. More broadly, Aon uses a variety of channels to facilitate open, ongoing and direct communication with colleagues, including open forums and town halls with executives, colleague support and pulse surveys, and engagement through our business resource groups. Management regularly reviews colleague survey results and wellbeing and engagement insights with the People & Wellbeing Sub‑Committee of the Governance/Nominating Committee and with the full Board. Director Selection and Shareholder Recommendations Consistent with our Corporate Governance Guidelines, the Governance/Nominating Committee seeks members representing a range of backgrounds and perspectives who combine a broad spectrum of experience and skills with a reputation for integrity. The Governance/Nominating Committee also considers whether a potential nominee would satisfy independence standards adopted by the Board and the requirements of the NYSE. The Governance/Nominating Committee has sole authority to retain third-party search firms to identify director candidates and to approve such search firm’s fees and other retention terms. In selecting nominees for director, the Governance/Nominating Committee considers professional background, reputation for integrity, leadership capabilities, and skills and experience in the context of the needs of the Board, as well as the composition of the Board as a whole, taking into account the Company's current and planned business and any anticipated succession of current directors. For more information regarding our directors, see page 4 of this proxy statement. When evaluating candidates for nomination as new directors, the Governance/Nominating Committee considers candidates with a variety of backgrounds, experiences and potential contributions to the Board.

  32. Director Nominee Composition

    When a vacancy exists on the Board due to the expansion of the size of the Board or the resignation or retirement of an existing director or as part of considering ongoing board succession planning, the Governance/Nominating Committee identifies and evaluates potential director nominees. The Governance/Nominating Committee recommends potential director candidates to the full Board, which is responsible for final approval of any director candidate. The effectiveness of the nomination process, including the criteria used for selecting nominees for director, is evaluated by the Board each year as part of its annual self-evaluation process and by the Governance/Nominating Committee as it evaluates and identifies director candidates. Our newest director, Jo Ann Jenkins, (who was appointed to the Board in August 2025) will stand for election at the Annual Meeting. Ms. Jenkins was identified by a third party search firm retained by the Governance/Nominating Committee. The Governance/Nominating Committee will consider shareholder recommendations for director nominees. Shareholder recommendations will be evaluated against the same criteria used to evaluate other director nominees, which are discussed under “Proposal 1 – Resolutions Regarding the Election of Directors” on page 8 of this proxy statement. Recommendations, together with the name and address of the shareholder making the recommendation, relevant biographical information regarding the proposed nominee and a description of any arrangement or understanding between the shareholder and the proposed nominee, together with any other information required by the Articles, should be sent to the Company Secretary. Shareholder recommendations for director candidates to stand for election at the 2027 annual general meeting must be submitted in writing to the Company Secretary, Aon plc, 15 George’s Quay, Dublin 2, Ireland. Recommendations will be forwarded to the Chair of the Governance/Nominating Committee for review and consideration. For information regarding compliance with the requirements applicable to shareholder nominations to the Board, see “Shareholder Proposals for 2027 Annual General Meeting” on page 73 of this proxy statement. Communications with the Board of Directors Shareholders and other interested parties may communicate with the Board, any committee of the Board, our independent Chair, or any of our directors by contacting the non-management directors of Aon plc, c/o the Company Secretary, 15 George’s Quay, Dublin 2, Ireland, or by sending an email to corporate.governance@aon.com. The non-management directors have established procedures for handling communications from shareholders and other interested parties. Communications are distributed to the Chair of the Governance/Nominating Committee, the full Board, the non-management directors, or to any individual director or directors as appropriate, depending on the facts and circumstances outlined in the communication. The Company Secretary will not distribute communications that are unrelated to the duties of the Board, such as spam, junk mail, mass mailings, business solicitations, and advertisements. Shareholder Engagement In 2025, we continued our active shareholder engagement program to deepen our understanding of shareholder perspectives on our long-term strategy, governance practices, executive compensation, corporate sustainability, human capital management and other key areas of shareholder interest. Over the course of the year, we conducted outreach to stewardship teams of our largest investors representing more than 50% of our outstanding shares, and met with shareholders holding over 42% of our outstanding shares, both before and after our 2025 Annual General Meeting. In these meetings, shareholders engaged with members of our senior management team and, in some instances, an independent Board member. We also met with shareholders who proactively requested engagement. Discussion topics generally included our results and strategy, industry trends, long-term expectations and financial guidance, corporate governance structure, Board composition and director refreshment and tenure, Board oversight of risk (including cybersecurity and AI), human capital management and succession planning, executive compensation (including performance-based awards), and corporate sustainability related matters. In addition, we conduct extensive year-round investor relations activities. Members of management regularly meet with investors to discuss Company strategies, financial and operating performance, capital allocation priorities and other matters of interest. Feedback from these engagement discussions is shared directly with our Board and its committees, including the Compensation Committee, as well as our senior executives. This input from shareholders informs our efforts to enhance our corporate governance, corporate sustainability and executive compensation practices and to improve the transparency and quality of our disclosures.

  33. Executive Compensation

    | Name and Principal Position | Year | Salary ($) | Bonus ($) | Stock Awards ($)(1) | Option Awards ($) | Non-Equity Incentive Plan Awards ($)(2) | Change in Pension Value and Nonqualified Deferred Compensation Earnings ($)(3) | All Other Compensation ($)(4) | Total ($) | | Gregory C. Case | 2025 | 1,500,000 | — | 68,769,941 | — | 2,437,500 | — | 1,035,198 | 73,742,639 | | President and Chief Executive | 2024 | 1,500,000 | — | 21,363,030 | — | 2,437,500 | — | 904,859 | 26,205,390 | | Officer | 2023 | 1,500,000 | — | 21,487,348 | — | — | — | 674,485 | 23,661,834 | | Edmund Reese | 2025 | 1,000,000 | 1,000,000(5) | 6,098,395 | — | 1,365,000 | 933 | 14,666 | 9,478,995 | | Executive Vice President and | 2024 | 500,000 | 1,300,000(5) | 4,915,524 | — | — | — | 6,178 | 6,721,701 | | Chief Financial Officer | | | | | | | | | | | Lisa Stevens | 2025 | 1,000,000 | — | 5,712,855 | — | 1,202,500 | — | 38,420 | 7,953,776 | | Executive Vice President and | 2024 | 1,000,000 | — | 5,705,132 | — | 1,040,000 | — | 40,774 | 7,785,906 | | Chief Administrative Officer | 2023 | 1,000,000 | — | 5,269,440 | — | — | — | 36,446 | 6,305,886 | | Andy Marcell | 2025 | 1,000,000 | — | 5,217,053 | — | 1,300,000 | — | 79,197 | 7,596,250 | | Executive Vice President and | | | | | | | | | | | CEO of Global Solutions | | | | | | | | | | | Mindy Simon | 2025 | 875,000 | — | 2,751,275 | — | 650,000 | 4,330 | 1,389,264 | 5,669,870 | | Executive Vice President and | 2024 | 768,750 | — | 2,542,663 | — | 552,500 | 4,085 | 579,074 | 4,447,072 | | Chief Operating Officer | | | | | | | | | |

  34. Executive Compensation

    | Name | Fees Earned or Paid in Cash ($) | Stock Awards ($)(1) | All Other Compensation ($)(2) | Total ($) | | Jose Antonio Álvarez | 145,000 | 225,211 | 10,000 | 380,211 | | Jin-Yong Cai | 160,330 | 225,211 | 158,797 | 544,338 | | Jeffrey C. Campbell | 180,000 | 225,211 | 10,000 | 415,211 | | Fulvio Conti | 85,577 | — | 20,000 | 105,577 | | Cheryl A. Francis | 175,000 | 225,211 | 10,000 | 410,211 | | Jo Ann Jenkins | 54,769 | 194,776 | 10,000 | 259,545 | | Adriana Karaboutis | 145,000 | 225,211 | 10,000 | 380,211 | | Lester B. Knight | 175,000 | 450,069 | 10,000 | 635,069 | | Richard C. Notebaert | 159,670 | 225,211 | 10,000 | 394,881 | | Gloria Santona | 145,000 | 225,211 | 10,000 | 380,211 | | Sarah Smith | 145,000 | 225,211 | 10,000 | 380,211 | | Byron O. Spruell | 160,330 | 225,211 | — | 385,541 | | James Stavridis | 145,000 | 225,211 | 10,000 | 380,211 |

  35. CEO Pay Ratio

    CEO Pay Ratio As required by the Dodd-Frank Wall Street Reform and Consumer Protection Act, we are providing the following information regarding the relationship between the annual total compensation of our median employee and the annual total compensation of our Chief Executive Officer, Mr. Case. For 2025, our last completed fiscal year, the median annual total compensation of our employees (excluding Mr. Case) was $89,327, and the annual total compensation of Mr. Case was $73,773,921 (this amount is approximately $31,000 higher than the total compensation amount reflected in the Summary Compensation Table appearing in this proxy statement because it also includes the value of certain personal benefits and compensation under our non-discriminatory benefit plans, which we also included when calculating the median employee’s annual total compensation). Based on this information and applicable SEC rules, our estimate of the ratio of Mr. Case’s annual total compensation to the median of the annual total compensation for all employees in 2025 was 826 to 1. Given the different methodologies that various public companies will use to determine an estimate of their pay ratio, the estimated ratio reported above should not be used as a basis for comparison between companies. To identify the median of the annual total compensation of all our employees, we first determined that our total global employee population (including full-time, part-time, and temporary employees) as of December 1, 2025, was 62,159. As permitted by SEC rules, which allow exclusion of a de minimis number of non-US employees in certain jurisdictions, we then excluded the following number of employees in the following jurisdictions, resulting in a total employee number (after applying the exclusions) of 61,390.

  36. CEO Pay Ratio

    | Excluded Jurisdiction | Number of Employees | | Gibraltar | 10 | | Indonesia | 143 | | Isle of Man | 23 | | Israel | 144 | | Macao | 8 | | Mauritius | 2 | | Morocco | 58 | | Oman | 38 | | Qatar | 18 | | Romania | 76 | | Turkey | 249 | | TOTAL | 769 | | Percentage of Total Population Excluded | 1.24% |

  37. CEO Pay Ratio

    To identify the median employee from this population, we determined that our compensation measure for this purpose would include: (1) an estimate of base salary, determined using the employee’s rate of pay and work schedule (part-time or full-time), and (for permanent employees who worked part of the year) adjusted for annualization as permitted under SEC rules; and (2) actual performance-based incentives paid under our annual incentive plan during 2025. We chose to use base salary and annual incentives as our compensation measure because these two components represent the most consistently used elements of remuneration across our global workforce (unlike, for example, long-term incentive equity awards, which are only granted to approximately 10% of our employee population). Further, these two components are the most consistently recorded items in our global compensation system. A small percentage of our global employee population is employed on a seasonal or temporary basis; due to difficulties in collecting consistent data regarding periods of actual employment, we estimated the base salary and annual incentive for this group to be zero. After identifying our median employee by applying the above-described compensation measure consistently to all employees included in the calculation, we identified and calculated the elements of that employee’s total compensation for 2025 and included the value of any personal benefits and compensation under our non-discriminatory benefit plans, as provided in applicable SEC rules. For the median employee, a substantial percentage (approximately 24%) of the total compensation amount was provided in the form of Company contributions to retirement funds and the cost of health and welfare coverage, which are in addition to the cash component of compensation.

  38. Pay vs. Performance

    Pay vs. Performance