Who are the largest reinsurance brokers?

Who Are the Largest Reinsurance Brokers in 2025?

When it comes to navigating the complex world of risk transfer, reinsurance brokers play a pivotal role in connecting insurers with reinsurers. As of 2025, Aon Reinsurance Solutions stands at the top of the industry, leading the pack with $1.997 billion in revenue. Known for its global reach and data-driven strategies, Aon has cemented its position through a combination of deep market expertise and integrated risk solutions.

Trailing closely behind is Guy Carpenter, the reinsurance arm of Marsh & McLennan, with $1.871 billion in revenue. With a strong presence in both property-casualty and specialty lines, Guy Carpenter leverages advanced analytics and capital markets solutions to help clients manage volatility and optimize capital.

Third on the list is Gallagher Re, part of Arthur J. Gallagher & Co., reporting $740 million in revenue. Over recent years, Gallagher has made strategic acquisitions and expanded its footprint in key international markets, boosting its competitive edge.

Coming in fourth is Howden Re, with $400 million in revenue. While historically smaller than its peers, Howden has been rapidly growing through aggressive expansion and a focus on agility and client customization—a strategy that’s paying off in an increasingly dynamic market.

These top brokers don’t just move billions in premiums—they shape how the global insurance industry manages risk in the face of climate change, cyber threats, and economic uncertainty. While the rankings reflect current financial performance, the real competition lies in innovation, client service, and the ability to adapt in a sector where resilience is everything.