Seatuck National Wildlife Refuge is located on the south shore of Long Island and is managed as part of the Long Island National Wildlife Refuge Complex. The refuge consists of 196 acres bordering the Great South Bay, separated from the Atlantic Ocean only by Fire Island. Situated in a heavily developed urban area, the refuge is an oasis for many species of migratory birds and waterfowl.

Approximately one half of the refuge consists of tidal marsh, which serves a vast number of waterfowl in the winter months. The refuge attracts waterbirds, white-tailed deer, red fox, and migratory songbirds and raptors. The Refuge has been classified as part of the larger Great South Bay, a significant coastal habitat. Management activities include forest and grassland protection and management, wetland restoration, wildlife nesting structure maintenance, and habitat restoration.