Aon plc

Aon plc (NYSE: AON) is a leading global professional services firm headquartered in Ireland and operating through its website at aon.com. The company serves clients in more than 120 countries across all market segments and nearly every industry, providing actionable analytic insight, risk capital expertise, and human capital solutions that help organizations make better risk and people decisions.

Aon operates through two primary reportable segments. The Risk Capital segment, which generated approximately 66% of 2025 revenue at $11,290 million, encompasses Commercial Risk Solutions, Reinsurance Solutions, and related services. Commercial Risk Solutions provides brokerage and consulting services including insurance and specialty brokerage, global risk consulting, captives management, and affinity programs across property, casualty, financial and professional lines, construction, transportation, energy, cyber, and other specialized areas. Reinsurance Solutions includes treaty reinsurance, facultative reinsurance, strategic consulting, and capital markets advisory services. The Human Capital segment contributed approximately 34% of revenue at $5,907 million and includes Health Solutions, which offers consulting, brokerage, consumer benefits, compensation, and talent advisory services, and Wealth Solutions, providing retirement consulting, pension administration, and investment advisory services.

The company employs approximately 60,000 colleagues globally and generated consolidated total revenue of $17,181 million in 2025. Aon's business model centers on higher-margin, capital-light professional services with recurring revenue streams and strong cash flow generation. The company generates revenues primarily through commissions from insurance and reinsurance companies, fees for consulting and analytics services, and client fees for advice and consulting services. Aon typically holds funds on behalf of clients, including premiums and claims in transit, which are segregated and invested in interest-bearing premium trust accounts.

The company competes with numerous global, regional, and local firms including Marsh McLennan, Willis Towers Watson, Arthur J Gallagher & Company, and Lockton Companies, as well as insurance companies marketing directly and emerging technology-enabled competitors. Aon's competitive advantages include its extensive global data and analytics capabilities, proprietary tools and platforms, integrated Risk Capital and Human Capital expertise, and the Aon United strategy that delivers coordinated solutions across the firm's service lines.