Family name was originally Cheese but his father changed it in 1915 to Cleese upon joining the Army.
Taught biology for two years at a preparatory school before attending Cambridge to study law.
Performed with the Cambridge Footlights comedy group where he met future Monty Python members Graham Chapman and Eric Idle.
Wrote and performed in the comedy revue Cambridge Circus, which played off-Broadway in New York.
Professional writing career began with The Dick Emery Show in 1963; later wrote for the satirical sketch show The Frost Report, which also featured Terry Jones and Michael Palin.
Cofounded Monty Python's Flying Circus in 1969; cowrote and appeared in the group's BBC series and their films, including Monty Python and the Holy Grail and Life of Brian.