Arthur J. Gallagher & Co., together with its subsidiaries, provides insurance and reinsurance brokerage, consulting, and third-party property/casualty claims settlement and administration services to businesses and organizations worldwide.

It operates in Brokerage and Risk Management segments. The Brokerage segment offers retail and wholesale insurance and reinsurance brokerage services; assists retail brokers and other non-affiliated brokers in the placement of specialized and hard-to-place insurance; and acts as a brokerage wholesaler, managing general agent, and managing general underwriter for distributing specialized insurance coverages to underwriting enterprises.

This segment also performs activities, including marketing, underwriting, issuing policies, collecting premiums, appointing and supervising other agents, paying claims, and negotiating reinsurance; and offers services in the areas of insurance and reinsurance placement, risk of loss management, and management of employer sponsored benefit programs.

The Risk Management segment provides contract claim settlement and administration services; and claims management, loss control consulting, and insurance property appraisal services.

The company offers its services through a network of correspondent brokers and consultants. It serves commercial, industrial, public, religious, and not-for-profit entities, as well as underwriting enterprises.

The company was founded in 1927 and is headquartered in Rolling Meadows, Illinois.