Billingsgate Island, also sometimes known as Bellingsgate Island, was an island off Cape Cod in Massachusetts in the United States. Originally settled as a fishing and whaling community as part of the town of Eastham, Massachusetts, Billingsgate Island was for a long time the site of a lighthouse used as a navigational aid in Cape Cod Bay. Local historians sometimes call it the Atlantis of Cape Cod.
The area, which is just south of Great Island at the mouth of Wellfleet Harbor, is now known as Billingsgate Shoal and is visible from mainland Wellfleet at Jeremy Point at low tide. When exposed it is used as a picnic and shellfishing spot; access is by boat. The shoal is frequented by birds, seals, and anglers.