Perth is a town in the Australian Island of Tasmania. It lies 20 km south of Launceston, on the Midland Highway. The town had a population of 3…Perth is a town in the Australian Island of Tasmania. It lies 20 km south of Launceston, on the Midland Highway. The town had a population of 3,233 at the 2021 census, and is part of the Northern Midlands Council.