Australia is a country in the Pacific Ocean.
Australia ( [ əˈstreɪliə ] , [ ɒ - ] , [ - ljə ] ) , officially the Commonwealth of Australia , is a country comprising the mainland of the Australian continent , the island of Tasmania and numerous smaller islands . Australia is a member of the United Nations , G20 , Commonwealth of Nations , ANZUS , Organisation for Economic Co-operation and Development ( OECD ) , World Trade Organization , Asia-Pacific Economic Cooperation , and the Pacific Islands Forum . Australia (continent) . The term Oceania is often used to denote the region encompassing the Australian continent and various islands in the Pacific Ocean that are not included in the seven-continent model . The Pacific Islands Forum is an inter-governmental organization that aims to enhance cooperation between the independent countries of the Pacific Ocean .