Clement Richard Attlee, 1st Earl Attlee, KG, OM, CH, PC, FRS (3 January 1883 – 8 October 1967) was a British Labour politician who served as the Prime Minister of the United Kingdom from 1945 to 1951, and as the Leader of the Labour Party from 1935 to 1955. He was also the first person to hold the office of Deputy Prime Minister, under Winston Churchill in the wartime coalition government, before leading the Labour Party to a landslide election victory over Churchill's Conservative Party in 1945. He was the first Labour Prime Minister to serve a full Parliamentary term, and the first to command a Labour majority in Parliament.

The government he led put in place the post-war settlement, based upon the assumption that full employment would be maintained by Keynesian policies, and that a greatly enlarged system of social services would be created – aspirations that had been outlined in the wartime Beveridge Report. Within this context, his government undertook the nationalisation of major industries and public utilities as well as the creation of the National Health Service. After initial Conservative opposition to Keynesian fiscal policy, this settlement was broadly accepted by all parties until Margaret Thatcher became Prime Minister in 1979 and neoliberalism became mainstream.

His government also presided over the decolonisation of a large part of the British Empire when India, Pakistan, Burma, Ceylon and Jordan obtained their independence. The British Mandate of Palestine also came to an end with the creation of Israel on the day of British withdrawal.