The Australian Labor Party (ALP), also simply known as Labor and originally spelt Labour, is the major centre-left political party in Australia, one of two major parties in Australian politics, along with the centre-right Liberal Party of Australia. It has been in Opposition in the federal parliament since the 2013 election. The ALP is a federal party, with political branches in each state and territory. They are currently in government in Victoria, Queensland, Western Australia, the Australian Capital Territory, and the Northern Territory. The Labor Party is the oldest political party in Australia.

The ALP was not founded as a federal party until after the first sitting of the Australian parliament in 1901. Nevertheless, it is regarded as descended from labour parties founded in the various Australian colonies by the emerging labour movement in Australia, formally beginning in 1891. Colonial labour parties contested seats from 1891, and federal seats following Federation at the 1901 federal election. The ALP formed the world's first labour party government as well as the world's first social-democratic government at a national level. At the 1910 federal election, Labor was the first party in Australia to win a majority in either house of the Australian parliament. At the federal and state/colony level, the Australian Labor Party predates, among others, both the British Labour Party and the New Zealand Labour Party in party formation, government, and policy implementation. Internationally, the ALP is a member of the Progressive Alliance, a network of social-democratic parties, having previously been a member of the Socialist International.