The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with others to conserve, protect, and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people."

Among the responsibilities of the USFWS are enforcing federal wildlife laws; protecting endangered species; managing migratory birds; restoring nationally significant fisheries; conserving and restoring wildlife habitats, such as wetlands; helping foreign governments in international conservation efforts; and distributing money to fish and wildlife agencies of U.S. states through the Wildlife Sport Fish and Restoration Program. The vast majority of fish and wildlife habitats are on state or private land not controlled by the United States government. Therefore, the USFWS works closely with private groups such as Partners in Flight and the Sport Fishing and Boating Partnership Council to promote voluntary habitat conservation and restoration.

The agency's directorship is currently led by Martha Williams. President Joe Biden appointed her to the position on March 8, 2022. She was previously the director of the Montana Department of Fish, Wildlife and Parks.

The USFWS employs approximately 8,000 people and is organized into a central administrative office in Falls Church, Virginia, eight regional offices, and nearly 700 field offices distributed throughout the United States.