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Australian Legal Research


Legal structure of Australia

The Commonwealth of Australia consists of six states and two major territories. These are often referred to by abbreviations, as follows:

  • Australian Capital Territory (ACT)
  • New South Wales (NSW)
  • Northern Territory (NT)
  • Queensland (Qld)
  • South Australia (SA)
  • Tasmania (Tas)
  • Victoria (Vic)
  • Western Australia (WA)

Minor territories include the Norfolk Islands (NF) plus seven other territories in the Indian Ocean, South Pacific Ocean and Antarctica. The ACT, the Northern Territory, and the Norfolk Islands are self-governing and have their own courts. The other territories are non-self-governing.

The Commonwealth of Australia came into existence on 1 January 1901, created from six formerly separate British colonies. The Australian Constitution was contained in an Act of the British Parliament, the Commonwealth of Australia Constitution Act (1900).

Federation meant that the six colonies (called states after Federation) surrendered some powers to form a central government to deal with national issues. However, each state maintained its own identity, with a state constitution, state laws, state courts, and so on.

The six Australian colonies were each founded at a different time. The legal system applicable to each also differs.

The Commonwealth Parliament can make laws only if given the power by the Constitution to do so. However, there are some areas of duplication. If the Commonwealth law does cover an area where there is also a state law, the state law is invalid to the extent that they are inconsistent. English common law applies in matters not covered by either Australian or state law.

As does the U.S., Australia has three branches of government: the executive, the legislative and the judiciary. There is also a separation of powers doctrine. One difference from the U.S., however, is that, under the Australian Constitution, all of the Ministers (department heads in the Executive Branch) must be Members of Parliament (the legislative branch).

Until the 1980s, the British Parliament and courts still maintained some jurisdiction over Australia; and some pre-1901 British laws remain in effect in the country today.


Prepared by Virginia McVarish, January 2006.

Revised by K. Storin Linitz, April 2008.

Revised by George Taoultsides, May 2010 - Present.