The Commonwealth of Australia is a union of six states and various territories. The Australian mainland is made up of five states and three territories, with the sixth state of Tasmania being made up of islands. In addition there are six island territories, known as external territories, and a claim to a territory in Antarctica.

All states and two of the three internal territories have their own parliaments and administer themselves; all remaining territories are administered by the Federal Government, but with Norfolk Island having some degree of self-government.