Eastchester Bay is a sound between City Island and the mainland Bronx in New York City, New York. Technically, it is not a bay, since it is open to larger bodies of water at both ends. The northern end connects via a narrow channel to Pelham Bay. The Hutchinson River empties into Eastchester Bay near the northern end. The lower portion of the bay opens onto the East River, Little Neck Bay, and Long Island Sound. Eastchester Bay is designated an Essential Fish Habitat by the National Marine Fisheries Service.