Leith is a semi-rural locality in the local government areas of Devonport and Central Coast in the North-west and west LGA region of Tasman…Leith is a semi-rural locality in the local government areas of Devonport and Central Coast in the North-west and west LGA region of Tasmania. The locality is about 10 kilometres east of the town of Ulverstone. The 2021 census recorded a population of 504 for the state suburb of Leith.