Monty Python's Flying Circus (also known as simply Monty Python) is a British surreal sketch comedy series created by and starring Graham Chapman, John Cleese, Eric Idle, Terry Jones, Michael Palin, and Terry Gilliam, who became known collectively as "Monty Python", or the "Pythons". The first episode was recorded at the BBC on 7 September 1969 and premiered on 5 October on BBC1, with 45 episodes airing over four series from 1969 to 1974, plus two episodes for German TV. A feature film adaptation of several sketches, And Now for Something Completely Different, was released in 1971.

The series stands out for its use of absurd situations, mixed with risqué and innuendo-laden humour, sight gags, and observational sketches without punchlines. Live-action segments were broken up with animations by Gilliam, often merging with the live action to form segues. The overall format used for the series followed and elaborated upon the style used by Spike Milligan in his groundbreaking series Q..., rather than the traditional sketch show format. The Pythons play the majority of the series's characters themselves, along with supporting cast members including Carol Cleveland (referred to by the team as the unofficial "Seventh Python"), Connie Booth (Cleese's first wife), series producer Ian MacNaughton, Ian Davidson, musician Neil Innes, and Fred Tomlinson and the Fred Tomlinson Singers for musical numbers.The programme came about as the six Pythons, having met each other through university and in various radio and television programmes in the 1960s, sought to make a new sketch comedy show unlike anything else on British television at the time. Much of the humour in the series' various episodes and sketches targets the idiosyncrasies of British life, especially that of professionals, as well as aspects of politics. Their comedy is often pointedly intellectual, with numerous erudite references to philosophers and literary figures and their works. The team intended their humour to be impossible to categorise, and succeeded so completely that the adjective "Pythonesque" was invented to define it and, later, similar material. However, their humour was not always seen as appropriate for television by the BBC, leading to some censorship during the third series. Cleese left the show following that series, and the remaining Pythons completed a final, shortened fourth series before ending the show.

The show became very popular in the United Kingdom, and after initially failing to draw an audience in the United States, gained American popularity after PBS member stations began airing it in 1974. The programme's success on both sides of the Atlantic led to the Pythons going on live tours and creating three additional films, while the individual Pythons flourished in solo careers. Monty Python's Flying Circus has become an influential work on comedy as well as in popular culture. The programming language Python was named by Guido van Rossum after the show, and the word spam, for junk email, took its name from a word used in a Monty Python sketch.