The top global insurance and reinsurance brokers, measured by total annual revenue, market capitalization, and international influence, traditionally include Marsh & McLennan Companies, Aon plc, Arthur J. Gallagher & Co., WTW (Willis Towers Watson), Hub International, Truist Insurance Holdings, Brown & Brown, Alliant Insurance Services, Acrisure, and Ryan Specialty. These industry-leading powerhouses dominate commercial insurance placement, risk management consulting, and wholesale brokerage operations worldwide.