John Marwood Cleese (pronounced /ˈkliːz/; born 27 October 1939) is an Academy Award-nominated English actor, comedian, writer, and film producer who is known for being a member of the group of comedians responsible for the sketch show Monty Python's Flying Circus and the four Monty Python films: And Now for Something Completely Different, Holy Grail, Life of Brian and The Meaning of Life.

Cleese co-wrote and starred in, with first wife Connie Booth, the much admired 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, and has made significant appearances in many films, including two James Bond films, The World Is Not Enough and Die Another Day, two Harry Potter films, Harry Potter and the Philosopher's Stone and Chamber of Secrets as Sir Nicholas de Mimsy-Porpington,also known as Nearly Headless Nick, and two Shrek films, Shrek 2 and Shrek 3 as Shrek's father-in-law, King Harold.

In Britain, he is also known for co-founding (with Yes Minister writer Antony Jay) the Video Arts production company, responsible for making training films.