Roger Rees (born 5 May 1944) is a Welsh actor. He is best known to American audiences for playing the characters Robin Colcord on the American television sitcom show Cheers and Lord John Marbury on the American television drama The West Wing. He won a Tony Award for his performance as the lead in The Life and Adventures of Nicholas Nickleby.
Rees was born in Aberystwyth, Wales, the son of Doris Louise (née Smith), a shop clerk, and William John Rees, a police officer. He started his career with the Royal Shakespeare Company and attended the Slade School of Fine Arts. Rees created the title role in the original production of the play The Life and Adventures of Nicholas Nickleby, winning both an Olivier Award and a Tony Award for Best Actor in a Play in 1982. He also starred in the original production of The Real Thing by Tom Stoppard in London in 1984.
Rees began to work in television during the 1970s, appearing opposite Laurence Olivier in The Ebony Tower (1984). From 1988 to 1991 he starred in the late 80s/early 90s British sitcom Singles, with actress and co-star Judy Loe. From 1989 to 1993 he also appeared intermittently on the long-running American TV series Cheers as the dashing, feckless English tycoon Robin Colcord. Later television appearances include My So-Called Life as substitute teacher Mr Racine, British Ambassador Lord John Marbury on The West Wing and James MacPherson on Warehouse 13 .