Sir John Major, KG, CH, ACIB (born 29 March 1943), is a former Prime Minister of the United Kingdom and former Leader of the Conservative Party. He held these posts from 1990 to 1997.

During his service as Prime Minister, the world went through a period of political and military transition after the end of the Cold War. This included the growing importance of the European Union and the debate surrounding Britain's ratification of the Maastricht Treaty. Major and his government were also responsible for the United Kingdom's exit from the Exchange Rate Mechanism (ERM) after Black Wednesday on 16 September 1992. Despite claiming the most votes in British electoral history in the 1992 General Election, the Conservatives lost the 1997 General Election in one of the worst electoral defeats since the Great Reform Act of 1832. After the defeat, Major resigned as the leader of the party, and was succeeded by William Hague.

Before becoming the Prime Minister, Major was a Cabinet minister under Margaret Thatcher. He served for brief periods as the Foreign Secretary and the Chancellor of the Exchequer, making him one of the few people to have served in three of the four Great Offices of State of the U.K.. He has since retired from politics, leaving the House of Commons just before the 2001 general election, and continues to be a sought-after speaker.