Mark Williams (born 22 August 1959) is an English actor, comedian, screenwriter and presenter. He is best known as one of the stars of the popular BBC sketch show The Fast Show, as well as for his role of Arthur Weasley in the Harry Potter films.
Williams was born in Bromsgrove, Worcestershire, attending North Bromsgrove High School. He was educated at Brasenose College, Oxford where he studied English. He became a member of the Mikron Theatre, a canal boat-based touring group in the 1980s.
He has appeared in numerous British television series, most notably The Fast Show. He also starred as Olaf Petersen in Red Dwarf and Kirk in Carrie and Barry.
He starred in the 1997 film The Borrowers with Tom Felton and Jim Broadbent. Later, the three would all be cast in the Harry Potter films, with Felton portraying Draco Malfoy and Broadbent portraying Horace Slughorn. Coincidentally, the antagonist of The Borrowers is named Ocious P. Potter.
In the Academy Award-winning film Shakespeare in Love, Williams portrayed Wabash, the stuttering actor who recited the Prologue and Epilogue in the production of Romeo and Juliet. More recently he has begun to receive notice for appearing in the second, third, fourth, fifth, and sixth Harry Potter films. On 3 July 2006 he appeared as an old roadie friend of Tommy Saxondale in the third episode of the BBC comedy series Saxondale.
Williams has also presented several documentary programmes: Mark Williams' Big Bangs on the history of explosives, a follow-up to previous series Mark Williams on the Rails, Industrial Revelations and More Industrial Revelations.
He is a supporter of both Aston Villa and Brighton & Hove Albion football clubs.