Weh Island (Indonesian: Pulau Weh), often known as Sabang after the city of which the island is administrated, is a small active volcanic island to the northwest of Sumatra, 45 minutes by fast regular ship or 2 hours by ferry from mainland, Banda Aceh. It was originally connected to the Sumatran mainland and became separated by sea after the volcano's last eruption in the Pleistocene era. The island is situated in the Andaman Sea.

The island is known for its ecosystem; the Indonesian government has declared 60 square kilometres (23 sq mi) of inland and sea around the island as a wildlife protection area. A rare megamouth shark species was found on shore and the island is the only habitat for the threatened toad, Duttaphrynus valhallae (formerly Bufo valhallae). Coral reef areas around the island are known for their large variety of fish species.