The Swan Coastal Plain in Western Australia is the geographic feature which contains the Swan River as it travels west to the Indian Ocean. The coastal plain continues well beyond the boundaries of the Swan River and its tributaries, as a geological and biological zone, one of Western Australia's Interim Biogeographic Regionalisation for Australia regions. It is also one of the distinct physiographic provinces of the larger West Australian Shield division.

Perth is the capital city of Western Australia. It is the fourth most populous city in Australia, with a population of over 2.3 million within Greater Perth. It is part of the South West Land Division of Western Australia, with the majority of Perth's metropolitan area on the Swan Coastal Plain between the Indian Ocean and the Darling Scarp. The city has expanded outward from the original British settlements on the Swan River, upon which its central business district and port of Fremantle are situated.