Gilliam has directed 13 feature films, including Time Bandits (1981), Brazil (1985), The Adventures of Baron Munchausen (1988), The Fisher King (1991), 12 Monkeys (1995), Fear and Loathing in Las Vegas (1998), The Brothers Grimm (2005), Tideland (2005), and The Imaginarium of Doctor Parnassus (2009). The only "Python" not born in Britain, he became a naturalized British subject in 1968 and formally renounced his American citizenship in 2006.
Gilliam was born in Minnesota but spent his high school and college years in Los Angeles. He started his career as an animator and strip cartoonist. He joined Monty Python as the animator of their works, but eventually became a full member and was given acting roles. He became a feature film director in the 1970s. Most of his films explore the theme of imagination and its importance to life, express his opposition to bureaucracy and authoritarianism, and feature characters facing dark or paranoid situations. His own scripts feature black comedy and tragicomic elements, as well as surprise endings.
In 1988, Gilliam and the other Monty Python members received the BAFTA Award for Outstanding British Contribution to Cinema. In 2009, Gilliam received the BAFTA Fellowship for lifetime achievement.