Thirty-one people (thirty men and one woman) have served as prime minister, the first of whom was Edmund Barton taking office on 1 January 1901 following federation of the British colonies in Australia.

They set the agenda and processes of cabinet meetings and has the final word where a collective decision cannot be reached.

National Cabinet, the primary inter-governmental decision-making forum between the federal government and the states, is also chaired by the prime minister.

[17] While called a cabinet, the body is merely a discussion forum and the principles of secrecy and collective decision making do not apply.

This uncertainty, and the possibility of a race between the governor-general and prime minister to dismiss the other, was a key question in the 1975 constitutional crisis.

In ordinary circumstances, the leader of the party or coalition that has the confidence of the House of Representatives is entitled to become prime minister and form a government.

The prime minister is formally appointed to the role by the governor-general under section 64 of the Australian Constitution,[22] however their choice is limited in normal circumstances to the individual with the confidence of the lower house.

There are no term limits for the prime minister, and they are generally entitled to continue in their role whilst they retain the confidence of the lower house.

Individuals most commonly cease to become prime minister after losing an election by not obtaining a majority in the lower house (at which point they generally become leader of the opposition or resign) or through replacement by their parliamentary party colleagues.

A prime minister may also lose their position following a vote of no confidence in the government or due to a failure to pass supply through the lower house.

Whether a prime minister is required to resign or call an election following an inability to pass supply through the Senate was the animating issue of the 1975 constitutional crisis.

The conventions of the Westminster system were thought to be sufficiently entrenched in Australia by the authors of the Constitution that it was deemed unnecessary to detail these.

Prior to that, in accordance with longstanding Australian constitutional practice, convention held that an outgoing prime minister would stay on as a caretaker until the full election results were tallied.

[40] Increases in the base salary of MPs and senators are determined annually by the independent Remuneration Tribunal.

Most prime ministers have chosen the Lodge as their primary residence because of its security facilities and close proximity to Parliament House.

More recently, John Howard used the Sydney prime ministerial residence, Kirribilli House, as his primary accommodation.

On her appointment on 24 June 2010, Julia Gillard said she would not be living in the Lodge until such time as she was returned to office by popular vote at the next general election, as she became prime minister by replacing an incumbent during a parliamentary term.

A Royal Australian Air Force operated Airbus KC-30A, transports the prime minister overseas, with two Boeing 737 MAX 8 planes available for shorter flights.

Reid (GCB, 1916),[68] Menzies (AK, 1976)[69] and Fadden (GCMG, 1958)[70] were awarded a second knighthood after leaving office.

This honour was awarded to Bruce (1927),[71] Lyons (1936),[72] Hughes (1941),[73] Page (1942),[74] Menzies (1951),[75] Holt (1967),[76] McEwen (1969),[77] Gorton (1971),[78] McMahon (1972),[79] and Fraser (1977),[80] mostly during office as prime minister.

[89][90] Bob Hawke was appointed a Companion in 1979, for service to trade unionism and industrial relations, before becoming prime minister in 1983.

In addition to these honours, all deceased former prime ministers of Australia currently have federal electorates named after them.

The longest-serving prime minister was Robert Menzies, who served in office twice: from 26 April 1939 to 28 August 1941, and again from 19 December 1949 to 26 January 1966.