Christopher Haden-Guest, 5th Baron Haden-Guest , is a British-American comedian, actor, writer, director, musician and Grammy Award-winning composer known as Christopher Guest. He is most famous for having written, directed and starred in several "mockumentary" films of the late 20th and early 21st centuries. He is frequently seen as the leader of a repertory film troupe, because he tends to re-use a core of actors from one film to the next.

He principally works in American film and television, despite holding a minor peerage in the United Kingdom. That barony has given him an additional measure of celebrity in the UK. He has publicly expressed a desire to see the House of Lords reformed as a democratically-elected chamber. Despite initial activity in the Lords, his career there was cut short by the House of Lords Act 1999.