All Brands Owned by Aon plc

What does Aon do?

Aon is the world's largest insurance broker by revenue. It advises clients on risk, places insurance and reinsurance, and consults on health, benefits, and retirement through its Risk Capital and Human Capital segments.

Is Aon publicly traded?

Yes. Aon plc trades on the New York Stock Exchange under ticker AON. It is domiciled in Dublin, Ireland.

Who founded Aon?

Aon was formed in 1982 by the merger of Ryan Insurance Group, founded by Patrick Ryan, and Combined International Corporation, founded by W. Clement Stone. Patrick Ryan led the combined company.

Where is Aon headquartered?

Aon is legally domiciled in Dublin, Ireland, at 15 George's Quay. Its principal operating centers are Chicago and London.

Who owns Aon?

Aon is publicly owned. Vanguard, BlackRock, and State Street are among the largest institutional shareholders. No controlling shareholder exists.

What is Aon's revenue?

Aon reported total revenue of $17.2 billion for fiscal 2025, split between $11.3 billion in Risk Capital and $5.9 billion in Human Capital.