William Armand Thomas "Tristan" Garel-Jones, Baron Garel-Jones, PC (28 February 1941 – 23 March 2020) was a British politician. A member of the Conservative Party, he served as the Member of Parliament (MP) for Watford from 1979 to 1997, before being made a life peer in 1997.

Following his election to Parliament, Garel-Jones served in various whip positions and also as a junior minister at the Foreign and Commonwealth Office.

Born in Gorseinon, Wales, the son of Bernard Garel-Jones and Meriel (née Williams), he and his family moved first to Las Palmas in the Canary Islands prior to settling in Madrid, Spain, when he was seven years old. Garel-Jones was educated at the King's School, Canterbury. His parents established successful language schools in Spain during this time. He moved back to the United Kingdom and worked as a merchant banker prior to embarking on a career in politics.

Garel-Jones first contested Caernarvon in February 1974, but was defeated by the future leader of Plaid Cymru, Dafydd Wigley. He was elected for Watford at the 1979 General Election.

Viewed as an effective whip who successfully delivered parliamentary votes in favour of Thatcher's legislation, Garel-Jones was nonetheless seen as a mixture of Machiavelli and Ivan the Terrible by the Thatcherite right-wing. Although his loyalty to Thatcher was never questioned, nor his ability to stamp out a rebellion, his party's "dry" (right wing) flank associated him with the Conservative "wets" (centrist) faction. He was seen as being to blame for the "growing wetness" of Thatcher's government. His formidable reputation as an effective enforcer in the whips' office was said to have been the inspiration for the fictional scheming Whip Francis Urquhart in the novel House of Cards and subsequent BBC TV drama adaptation.

Others who knew him said "where Dobbs’ character was a cold, machiavellian schemer, Garel-Jones was in reality a warm and enthusiastic person who cared deeply about human rights, equality, and the advancement of humanist ideals."

Garel-Jones was a leading pro-European, and remained so, despite the Conservative party moving to a more Eurosceptic position by the end of the Thatcher era. This created suspicion among right-wing Thatcherites, who thought of him as one of the "wets". However, he voted for Margaret Thatcher in the first round of the leadership challenge by Michael Heseltine, but reserved the right to vote against her if it went to a second round. He subsequently voted for Douglas Hurd.

After he stepped down from the House of Commons in 1997, he was given a life peerage as Baron Garel-Jones, of Watford in the County of Hertfordshire.