The 1975 Australian constitutional crisis, also known simply as the Dismissal, culminated on 11 November 1975 with the dismissal from office of the Prime Minister, Gough Whitlam of the Australian Labor Party (ALP), by Governor-General Sir John Kerr, who then commissioned the Leader of the Opposition, Malcolm Fraser of the Liberal Party, as Prime Minister. It has been described as the greatest political and constitutional crisis in Australian history.

The Labor Party under Gough Whitlam came to power in the election of 1972, ending 23 years of consecutive Liberal-Country Coalition government. Labor won a majority in the House of Representatives of 67 seats to the Coalition's 58 seats, but faced a hostile Senate, half of which had been elected in 1967 and half of which had been elected in 1970 (the two houses had been out of sync since an early election in 1963) and in which the Democratic Labor Party, who usually supported the Liberal-Country Coalition, held the balance of power. In May 1974, after the Senate voted to reject six of Labor's non-supply bills, Whitlam advised then-Governor General Sir Paul Hasluck to call a double dissolution election. The election saw Labor re-elected with its net House of Representatives majority reduced from 9 to 5 seats, although it gained 5 seats in the Senate. With the two houses of Parliament still deadlocked, pursuant to section 57 of the Australian Constitution, Whitlam was able to narrowly secure passage of the six "trigger bills" of the earlier double dissolution election in a joint sitting of Parliament on 67 August 1974, the only such sitting held in Australia's history.

Whitlam's tenure in office proved highly turbulent and controversial, and in October 1975, the Opposition under Malcolm Fraser used its control of the Senate to defer passage of appropriation bills needed to finance government expenditure, which had already been passed by the House of Representatives. Fraser and the Opposition stated that they would continue to block supply in the Senate unless Whitlam called a fresh election for the House of Representatives, and urged Governor-General John Kerr, who had been appointed Governor-General on Whitlam's advice in July 1974, to dismiss Whitlam unless Whitlam acceded to their demand. Whitlam believed that Kerr would not dismiss him as Prime Minister, and Kerr did nothing to make Whitlam believe that he might be dismissed.

On 11 November 1975, the crisis came to a head as Whitlam went to seek Kerr's approval to call a half-Senate election in an attempt to break the parliamentary deadlock. Kerr did not accept Whitlam's request, and instead dismissed him as Prime Minister and appointed the Leader of the Opposition Malcolm Fraser as caretaker Prime Minister on the understanding that Fraser would immediately call a general election. Acting quickly before all ALP parliamentarians became aware of the change of government, Fraser and his parliamentary allies were able to secure passage of the supply bills through the Senate and advised Kerr to dissolve Parliament for a double dissolution election. Fraser and his Liberal-Country Coalition were elected with a massive majority in the federal election held the following month.

The events of the Dismissal led to only minor constitutional change. The Senate retained its power to block supply, and the Governor-General the power to dismiss government ministers; however, these powers have not since been used to force a government from office. Kerr was widely criticised by Labor supporters for his actions, resigned early as Governor-General, and lived much of his remaining life abroad.

The Liberal–National Coalition, commonly known simply as "the Coalition", is an alliance of centre-right political parties that forms one of the two major groupings in Australian federal politics. The two partners in the Coalition are the Liberal Party of Australia and the National Party of Australia (the latter previously known as the Country Party and the National Country Party). Its main opponent is the Australian Labor Party (ALP); the two forces are often regarded as operating in a two-party system. The Coalition has been in government since the 2013 federal election, most recently being re-elected in the 2019 Australian federal election. The group is led by Scott Morrison as Prime Minister of Australia since August 2018.

The two parties in the Coalition have different voter bases, with the Liberals – the larger party – drawing most of their vote from urban areas and the Nationals operating almost exclusively in rural and regional areas. They occupy a broadly similar place on the centre-right of the political spectrum, although certain ideologies are more prevalent in each party. The partnership between the two current parties dates back to 1946, shortly after the Liberal Party was formed, and has continued almost uninterrupted since then. The Country Party also maintained similar alliances with the Liberal Party's predecessors, the United Australia Party and Nationalist Party, and similar parties at state level. The first such federal arrangement was formed in 1923, as a solution to the hung parliament that resulted from the 1922 federal election.

The Liberals and Nationals maintain separate organisational wings and separate parliamentary parties, but co-operate in various ways determined by a mixture of formal agreements and informal conventions. There is a single Coalition frontbench, both in government and in opposition, with each party receiving a proportionate number of positions. By convention, the leader of the Liberal Party serves as the overall leader, serving as prime minister when the Coalition is in government and leader of the opposition when the Coalition is in opposition. The leader of the National Party becomes the deputy prime minister during periods of conservative government. The two parties co-operate on their federal election campaigns, run joint Senate tickets in most states, and generally avoid running candidates against each other in the House of Representatives.

A merger of the Liberals and Nationals has been suggested on a number of occasions, but has never become a serious proposition. The relationship between the two parties varies at state and territory level. The situation in New South Wales and Victoria broadly mirrors that at federal level, while in Western Australia the parties are much more independent of each other. In the Northern Territory the territorial parties merged in 1974 to form the Country Liberal Party (CLP), and in 2008 the Queensland state-level parties merged, forming the Liberal National Party of Queensland (LNP). LNP and CLP members elected to federal parliament do not form separate parliamentary parties, joining either the Liberals or Nationals. In South Australia, Tasmania and the ACT, the Nationals have no sitting MPs and little or no organisational presence.