Bradley John Walsh is an English actor, television presenter, comedian, singer, and former professional footballer.

Graham O'Brien is a fictional character created by Chris Chibnall and portrayed by Bradley Walsh in the long-running British sci-fi television series Doctor Who. A retired bus driver from Essex who is in remission from cancer, the character is portrayed as an everyman. In the show's eleventh series, starting with the first episode, he served as a companion of the thirteenth incarnation of the alien time traveller known as the Doctor until the 2021 New Year's Special "Revolution of the Daleks".