perth | country | australia <sep> perth (nyungar: boorloo) is the capital and largest city of the australian state of western australia it is the fourth most populous city in australia and oceania, with a population of 21 million (80% of the state) living in greater perth in 2020 perth is part of the south west land division of western australia, with most of the 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 the city's central business district and port of fremantle are situated perth is located on the traditional lands of the whadjuk noongar people, where aboriginal australians have lived for at least 45,000 yearscaptain james stirling founded perth in 1829 as the administrative centre of the swan river colony 
perth is in australia.perth is the fourth most populous city in australia and oceania