Halvmånesundet is a strait between Halvmåneøya and Edgeøya, Svalbard. It is located east of the peninsula with the headland Negerpynten. The strait has a width of about 1.8 nautical miles at the narrowest point.
Coordinates: 77°17′18″N 23°01′00″E / 77.2883°N 23.0166°E