Seal Beach National Wildlife Refuge is a 1.5-square-mile protected wetland in Seal Beach, California, established in 1972 and formally defined in 1974 within Naval Weapons Station Seal Beach. Managed by the United States Fish and Wildlife Service and the Department of the Navy, it is an important stop on the Pacific Flyway and supports great blue herons and endangered wetland birds including the California clapper rail, California least tern, and Belding's Savannah sparrow. Its salt marsh, mudflats, channels, and subtidal basins sustain birds, fish, and invertebrates. Shaped by subsidence, military use, and habitat management, it remains a restricted refuge devoted to conservation and research.