Tasman Island is an oval island, with an area of 1.2 km², in south-eastern Australia. It is part of the Tasman Island Group, lying close to the south-eastern coast of Tasmania around the Tasman Peninsula, and is in the Tasman National Park. It is a plateau surrounded by steep dolerite cliffs, with its highest point 300 m asl and an average plateau height of 280 m asl.