John Ronald Simm (born 10 July 1970) is an English actor, director and musician.
He has been nominated twice for the BAFTA Award for Best Actor, and is a Laurence Olivier Award nominee for best actor.
He is best known for playing Sam Tyler in Life on Mars, and The Master in Doctor Who.
His other television credits include: State of Play, The Lakes, Crime and Punishment, Exile, Prey and Cracker.
His films include Wonderland, Everyday, Boston Kickout, Human Traffic and 24 Hour Party People.