Samuel Barnett (born 25 April 1980) is an English actor. He has performed on stage, film, television and radio, and achieved recognition for his work on the stage and film versions of The History Boys by Alan Bennett. His television performances include roles in the BBC comedy Twenty Twelve and in the Showtime drama Penny Dreadful. On 29 March 2016 it was announced that he had been cast as Dirk Gently in the BBC America adaptation of the Dirk Gently's Holistic Detective Agency book series by Douglas Adams.