Graham Arthur Chapman was a British comedian and writer. He was one of the six Monty Python members and lead actor in their two narrative films (King Arthur in Monty Python and the Holy Grail and Brian in Life of Brian).

Chapman studied medicine at Emmanuel College at the University of Cambridge, where he began writing comedy with classmate John Cleese. He qualified as a doctor at the Barts Hospital Medical College, but never actually practiced medicine. The duo wrote professionally on the BBC during the 1960s, primarily for the ubiquitous David Frost but also for Marty Feldman.

They joined Michael Palin, Terry Jones, Eric Idle and American artist Terry Gilliam for Monty Python's Flying Circus in 1969. Cleese and Chapman's classic Python sketches included "The Ministry of Silly Walks" and "Dead Parrot."

One of his particularly famous sketches was the character of The Colonel, a stuffy army officer who occasionally appeared out of nowhere to order the end of a sketch for being too silly. After Cleese left the show in 1973, Chapman wrote alone for the final season. He then developed a number of movie scripts, most notably Yellowbeard, where he starred with Cleese, Peter Cook, and Cheech and Chong.

The remaining Python members have acknowledged that Chapman was exasperating to work with, and difficult to know. But none of the other Pythons could have played King Arthur or Brian as well as Chapman.

After his death, speculation of a Python revival inevitably faded—as Idle said, "we would only do a reunion if Graham came back from the dead. So we're negotiating with his agent."