Samuel Barnett was born 25 April 1980. He is from London, but was raised in Whitby, in North Yorkshire, England. He started performing at an early age, and studied acting at LAMDA. Barnett is Jewish on his father's side, with his paternal grandparents having immigrated from Poland; his mother is a Quaker. He is one of five children.
Sam appeared in the original London stage production of Alan Bennett's play The History Boys, as well as in the New York, Sydney, Wellington and Hong Kong productions and radio and film versions of the play. He had been involved in The History Boys from its very first reading.In 2009 he will play John Everett Millais in the BBC series Desperate Romantics, and Joseph Severn in the film Bright Star.
Samuel was nominated for Evening Standard Award as Most Promising Newcomer for his role in The Marriage of Figaro in 2002. He also won Best Newcomer & Best Supporting Actor in a play at the Whatsonstage.com Theatregoers Choice Awards for his work on the original West End production of The History Boys. He was nominated for the 29th annual Olivier Award for Performance in a Supporting Role. He won a 2006 Drama Desk Award and was nominated for a 2006 Tony Award for his work on the Broadway production. Barnett was nominated for the 2006 British Independent Film Award for Most Promising Newcomer (On Screen) for his work on the film version of The History Boys.