Brisbane is the capital and largest city of the state of Queensland and the third-most populous city in Australia, with a population of approximat…Brisbane is the capital and largest city of the state of Queensland and the third-most populous city in Australia, with a population of approximately 2.8 million. Brisbane lies at the centre of South East Queensland, an urban agglomeration with a population of over 4 million. The central business district is situated within a peninsula of the Brisbane River about 15 km from its mouth at Moreton Bay. Brisbane's metropolitan area sprawls over the hilly floodplain of the Brisbane River Valley between Moreton Bay and the Taylor and D'Aguilar mountain ranges, encompassing several local government areas, most centrally the City of Brisbane. The demonym of Brisbane is Brisbanite.