Constitution of Australia

The Constitution of Australia (or Australian Constitution) is a written constitution that is supreme law in Australia. It establishes Australia as a federation under a constitutional monarchy and outlines the structure and powers of the Australian government's three constituent parts, the executive, legislature, and judiciary.

Commonwealth of Australia Constitution
Original titleCommonwealth of Australia Constitution Act 1900 (UK), s. 9
Ratified6 July 1900 (1900-07-06)
Date effective1 January 1901 (1901-01-01)
SystemFederal Government
ExecutiveSee Australian Government
JudiciarySee Judiciary of Australia
AmendmentsSee Referendums in Australia
Last amendedSee 1977 Australian referendum (Retirement of Judges)
LocationNational Archives of Australia
Author(s)Constitutional Conventions, 1891 and 1897-98
SignatoriesQueen Victoria
SupersedesAustralian Colonies Government Act 1850
Commonwealth of Australia Constitution Act at Wikisource

The constitution was drafted between 1891 and 1898, through a series of conventions conducted by representatives of the six self-governing British colonies in Australia. The final draft was then approved in a set of referendums from 1898 to 1900. The British government objected to some elements of the final draft, but a slightly modified form was enacted as section 9 of the Commonwealth of Australia Constitution Act 1900, an act of the Parliament of the United Kingdom. The act was given royal assent on 9 July 1900, was proclaimed on 17 September 1900, and entered into force on 1 January 1901.[1][2] The constitution gave the six colonies the status of states within the new federation.

Australian constitutional law has developed from the interpretation of the constitution by the High Court. As well as its textual provisions, the constitution is understood to incorporate various unwritten constitutional conventions and ideas derived from the Westminster system, one of which is responsible government. Although the 1900 act initially derived its legal authority from the UK Parliament, the present understanding of the High Court and some academics is that it now derives its legal authority from the Australian people.[3] Other documents of constitutional significance to Australia include the Statute of Westminster and the Australia Act 1986.

The constitution may only be amended by referendum, through the procedure set out in section 128. Amendments require a "double majority" – a nationwide majority as well as a majority of voters in a majority of states. This has contributed to the low number of successful amendments; forty-four referendums have been held but only eight amendments have been passed, most recently in 1977. Ongoing debates exist regarding further proposals for amendment, notably including the inclusion of a preamble, the replacement of the monarchy with a republic, and the addition of an Indigenous voice to government.