Ramsay MacDonald becomes the first Labour Prime Minister of the United Kingdom.

James Ramsay MacDonald was a British statesman and politician who served as Prime Minister of the United Kingdom. The first two of his governments belonged to the Labour Party, where he led a minority Labour government for nine months in 1924 and again between 1929 and 1931. In 1931, MacDonald was expelled from the Labour Party, after he formed a National Government dominated by the Conservative Party and supported by only a few Labour members, his premiership of which lasted until 1935.

The Labour Party, often referred to as Labour, is a political party in the United Kingdom that sits on the centre-left of the political spectrum. The party has been described as an alliance of social democrats, democratic socialists and trade unionists. It is one of the two dominant political parties in the United Kingdom; the other being the Conservative Party. Labour has been led by Keir Starmer since 2020, who became Prime Minister of the United Kingdom following the 2024 general election. To date, there have been 12 Labour governments and seven different Labour Prime Ministers – MacDonald, Attlee, Wilson, Callaghan, Blair, Brown and Starmer.

The prime minister of the United Kingdom is the head of government of the United Kingdom. The prime minister advises the sovereign on the exercise of much of the royal prerogative, chairs the Cabinet, and selects its ministers. Modern prime ministers hold office by virtue of their ability to command the confidence of the House of Commons, so they are invariably members of Parliament.