States and territories of Australia

The states and territories are the national subdivisions and second level of government of Australia. The states are partially sovereign, administrative divisions that are self-governing polities, having ceded some sovereign rights to the federal government. They have their own constitutions, legislatures, executive governments, judiciaries and law enforcement agencies that administer and deliver public policies and programs. Territories can be autonomous and administer local policies and programs much like the states in practice, but are still legally subordinate to the federal government.

Australia has six federated states: New South Wales (including Lord Howe Island), Queensland, South Australia, Tasmania (including Macquarie Island), Victoria, and Western Australia. Australia also has ten federal territories, out of which three are internal territories: the Australian Capital Territory, the Jervis Bay Territory, and the Northern Territory on the Australian mainland; and seven are external territories: the Ashmore and Cartier Islands, the Australian Antarctic Territory, Christmas Island, the Cocos (Keeling) Islands, the Coral Sea Islands, Heard Island and McDonald Islands, and Norfolk Island that are offshore dependent territories. Every state and internal territory (except the Jervis Bay Territory) is self-governing with its own independent executive government, legislature, and judicial system, while the rest only have local government status overseen by federal departments.

State and territory governments may legislate on matters concerning their citizens, subject to the limits of the federal constitution (notably section 51 and section 109). Each state and internal territory (except Jervis Bay Territory) has its own legislature, although the Federal Parliament can override territorial legislation. The federal High Court of Australia acts as a final court of appeal for all matters, and has the authority to override any state judiciary. While all states and internal territories have their own judicial system (subject to appeal to the High Court), most external territories are subject to the judiciary and legislature of either a state or internal territory. Excluding the Heard Island and McDonald Islands and the Australian Antarctic Territory (which are governed by the Department of Climate Change, Energy, the Environment and Water), the external territories are governed by the federal Department of Infrastructure, Transport, Regional Development, Communications and the Arts. Norfolk Island had its own legislature from 1979 to 2015.

Each state is a successor to a historical British colony, and each has its own constitution. The Australian Capital Territory (ACT) and Northern Territory for the most part operate indistinguishably from the states (for example, both have representation in the Parliament since 1948 and in the Senate since 1975), even though they do not have constitutional status as states and territorial legislation can be overridden.

Surrounded by the Indian, Pacific, and Southern oceans, Australia is separated from Maritime Southeast Asia and New Guinea by the Arafura Sea, the Timor Sea, and the Torres Strait, from Island Melanesia by the Coral Sea, and from New Zealand by the Tasman Sea. The world's smallest continent, Australia is also the sixth-largest country by land area and sometimes considered the world's largest island. Australia has a mainland coastline of 32,994 kilometres (20,502 mi) and claims an exclusive economic zone of about 8,200,000 square kilometres (3,200,000 sq mi).

At Federation in 1901, what is now the Northern Territory was within South Australia, what are now the Australian Capital Territory and Jervis Bay Territory were within New South Wales, and the Coral Sea Islands were part of Queensland. Ashmore and Cartier Islands was accepted by Australia in 1934 and was annexed to the Northern Territory prior to adoption of the Statute of Westminster in 1942, deemed effective from 1939; it has thus become part of Australia.

Each external territory is regulated by an Act of the federal Parliament. These Acts contain the majority of provisions determining the legal and political structure applying in that external territory. Under s 122 of the Australian Constitution the federal Parliament has plenary power to make laws for all territories including all external territories. The Cocos (Keeling) Islands voted for integration in 1984. Together with Christmas Island, these two territories comprise the Australian Indian Ocean Territories. Commonwealth laws apply automatically to the territories unless expressly stated otherwise and residents of both external territories are associated with Northern Territory for federal elections. They are, thus, constitutionally part of Australia.

The Heard Island and McDonald Islands, although uninhabited, are treated as constitutionally part of Australia by the central government.