Roger Rees (5 May 1944 – 10 July 2015) was a Welsh actor and director, widely known for his stage work. He won an Olivier Award and a Tony Award for his performance as the lead in The Life and Adventures of Nicholas Nickleby. He also received Obie Awards for his role in The End of the Day and as co-director of Peter and the Starcatcher. Rees was posthumously inducted into the American Theater Hall of Fame in November 2015.

He was widely known to American television audiences for playing the characters Robin Colcord in Cheers and Lord John Marbury in The West Wing.