Kenneth Harry Clarke, Baron Clarke of Nottingham (born 2 July 1940) is a British politician who served as Home Secretary from 1992 to 1993 and Chancellor of the Exchequer from 1993 to 1997. A member of the Conservative Party, he was Member of Parliament (MP) for Rushcliffe from 1970 to 2019, serving as Father of the House of Commons between 2017 and 2019.

Clarke served in the Cabinets of Margaret Thatcher and John Major as Chancellor of the Duchy of Lancaster from 1987 to 1988, Health Secretary from 1988 to 1990, and Education Secretary from 1990 to 1992. He held two of the Great Offices of State as Home Secretary and Chancellor of the Exchequer.

President of the Tory Reform Group since 1997, Clarke is a one-nation conservative who identifies with economically and socially liberal views. He contested the Conservative Party leadership three times—in 1997, 2001 and 2005—being defeated each time. Opinion polls indicated he was more popular with the general public than with his party, whose generally Eurosceptic stance did not chime with his pro-European views.

Under the coalition government of David Cameron, he returned to the Cabinet as Justice Secretary and Lord Chancellor from 2010 to 2012 and Minister without Portfolio from 2012 to 2014. He was also the United Kingdom Anti-Corruption Champion from 2010 to 2014.

The Conservative Whip was withdrawn from him in September 2019 because he and 20 other MPs voted with the Opposition on a motion; for the remainder of his time in Parliament he sat as an independent, though still on the government benches. He stood down as an MP at the 2019 general election and was thereafter made a Conservative life peer in the House of Lords in 2020.

Clarke is President of the Conservative Europe Group, Co-President of the pro-EU body British Influence and Vice-President of the European Movement UK. Described by the press as a 'Big Beast' of British politics, his total time as a minister is the fifth-longest in the modern era. He has spent over 20 years serving under Prime Ministers Edward Heath, Margaret Thatcher, John Major and David Cameron. He was one of only five ministers (Tony Newton, Malcolm Rifkind, Patrick Mayhew and Lynda Chalker are the others) to serve throughout the whole 18 years of the Thatcher-Major governments, which represents the longest uninterrupted ministerial service in Britain since Lord Palmerston in the early 19th century.

Kenneth Harry Clarke was born in Nottingham and was christened with the same name as his father, Kenneth Clarke, a mining electrician. The younger Clarke spent his early years in Langley Mill, Derbyshire. He won a scholarship to the independent Nottingham High School before going up to read law at Gonville and Caius College, Cambridge, where he graduated with an upper second honours degree. Clarke initially held Labour sympathies, and his grandfather was a Communist, but while at Cambridge he joined the Conservative Party.

As Chairman of the Cambridge University Conservative Association (CUCA), Clarke invited former British Fascist leader Sir Oswald Mosley to speak for two years in succession, prompting some Jewish students (including his future successor at the Home Office, Michael Howard) to resign from CUCA in protest. Howard then defeated Clarke in one election for the presidency of the Cambridge Union, but Clarke became President of the Cambridge Union a year later, being elected on 6 March 1963 by a majority of 56 votes. Clarke opposed the admission of women to the Union, and is quoted as saying upon his election, "The fact that Oxford has admitted them does not impress me at all. Cambridge should wait a year to see what happens before any decision is taken on admitting them."