Wannanup is a residential suburb in Western Australia, located 12 kilometres southwest of Mandurah and 87 kilometres south-southwest of the state capital, Perth. It is surrounded on three sides by water – the Indian Ocean to the west, the Harvey Estuary to the east and the Dawesville Channel to the south – and is home to the Port Bouvard development. It is one of four suburbs which lie on an island created by the building of the Dawesville Channel.