John Marwood Cleese (/ˈkliːz/; born 27 October 1939) is an English actor, comedian, writer, and film producer. He achieved success at the Edinburgh Festival Fringe and as a scriptwriter and performer on The Frost Report. In the late 1960s he became a member of Monty Python, the comedy troupe responsible for the sketch show Monty Python's Flying Circus and the four Monty Python films: And Now for Something Completely Different, The Holy Grail, Life of Brian, and The Meaning of Life.

In the mid 1970s, Cleese and his first wife, Connie Booth, co-wrote and starred in the British sitcom Fawlty Towers. Later, he co-starred with Kevin Kline, Jamie Lee Curtis, and former Python colleague Michael Palin in A Fish Called Wanda and Fierce Creatures. He also starred in Clockwise, and has appeared in many other films, including two James Bond films as Q, two Harry Potter films, and three Shrek films.

With Yes Minister writer Antony Jay he co-founded Video Arts, a production company making entertaining training films.