Mistaken Island is an uninhabited island in the Dampier Archipelago, in the Pilbara, Western Australia.
Its area is about . It is connected to East Mid Intercourse Island, and thence to the mainland, by a causeway/bridge.
The island is adjacent to the Dampier salt evaporation pond and has been used as a salt port by Dampier Salt since 1972. Over are exported annually, with the bulk of this going to industrial use.