Brian Braddock is a fictional superhero appearing in British and American comic books published by Marvel Comics, originally as Captain Britain. Created in 1976 by writer Chris Claremont and artist Herb Trimpe, with later contributions from Alan Moore and Alan Davis, he first appeared in Captain Britain Weekly #1. The character was initially intended exclusively for the British comics market.

Endowed with extraordinary powers by the legendary magician Merlyn and his daughter Roma, Brian becomes Captain Britain, assigned to be the champion of the British Isles and its peoples, as well as the defender of Earth-616 as a member of the multiversal Captain Britain Corps. Following his corruption by Morgan le Fay, his twin sister Betsy reclaimed the mantle of Captain Britain, with Brian taking up the moniker Captain Avalon as defender of Avalon.