Western Australia Flag Coat of arms Slogan or nickname The Wildflower State; The Golden State Other Australian states and territories Coordinates 26°S 121°E / 26°S 121°E / -26; 121 Coordinates: 26°S 121°E / 26°S 121°E / -26; 121 Capital city Perth Demonym Western Australian, West Australian, Sandgroper (colloquial) Government Constitutional monarchy • Governor Kim Beazley • Premier Mark McGowan (Labor) Australian state • Established (as the Swan River Colony) 2 May 1829 • Responsible government 21 October 1890 • Federation 1 January 1901 • Australia Act 3 March 1986 Area • Total 2,645,615 km² (1st) 1,021,478 sq mi • Land 2,529,875 km² 976,790 sq mi • Water 115,740 km² (4.37%) 44,687 sq mi Population (September 2017) [1] ...