John Ronald Simm (born 10 July 1970) is an English actor, director, and musician. He is best known for playing Sam Tyler in Life on Mars, the Master in Doctor Who, and Det Supt Roy Grace in Grace. His other television credits include State of Play, The Lakes, Crime and Punishment, Exile, Prey, and Cracker. His film roles include Wonderland, Everyday, Boston Kickout, Human Traffic and 24 Hour Party People. He has twice been nominated for the BAFTA Award for Best Actor and has won the 2014 Royal Television Society award in the Best Performance in a Single Drama or Drama Series (Male) category for his work on the crime thriller series Prey..