Birth Date: 1959
Biography: Mark Williams (born 1959) is a British actor, comedian, scriptwriter and presenter. He is best known as one of the stars of the popular BBC sketch show, The Fast Show. He also plays Olaf Petersen in Red Dwarf.
More recently he has appeared as Arthur Weasley in the second and third Harry Potter films.
He also presents a documentary series titled Mark Williams on the Rails, a follow on from a previous series called Industrial Revelations.