The United Australia Party (UAP) was an Australian political party that was founded in 1931 and dissolved in 1945. It was the political successor to the Nationalist Party of Australia (1917–1931) and was succeeded by the Liberal Party of Australia (1945) as the main anti-Labor party. The party was in government in Australia for much of the 1930s, through Australia's recovery from the Great Depression under Joseph Lyons and into the early stages of World War II under Robert Menzies.