Mark Williams (born August 22, 1959) is an English actor, comedian, presenter and screenwriter. He first achieved widespread recognition as one of the central performers in the popular BBC sketch show The Fast Show. His film roles include Horace in the 1996 adaptation of 101 Dalmatians and Arthur Weasley in seven of the Harry Potter films. He made recurring appearances as Brian Williams in the BBC television series Doctor Who and as Olaf Petersen in Red Dwarf. Since 2013, Williams has portrayed the title character in the long-running BBC series loosely based on the Father Brown short stories by G. K. Chesterton.

Filmography

• 2025Dream Hacker — Edgar Wainwright
• 2025The Secret Santa Project — Leon
• 2024Robin and the Hoods — The Mayor
• 2023Surprised by Oxford — Professor Nuttham
• 2023The Effects of Lying
• Here We Go — Frank
• Sister Boniface Mysteries — Father Brown
• 2022Super Villans — Self, Writer, Presenter
• 2021The Dark Channel — Mabuse
• 2020The Fast Show: Just a Load of Blooming Catchphrases — Writer
• 2020The Fast Show: More Blooming Catchphrases — Self/Various Characters
• 2018Early Man — Barry (voice)
• 2017Heidi: Queen of the Mountain — Henry
• 2016Golden Years — Phil
• 2016Red Top — Police Commissioner Hamish Pritchard
• 2016We're Going on a Bear Hunt — Dad (voice)
• The Musketeers — Pathologist
• Blandings — Sebastian Beach
• Father Brown — Father Brown
• 2013The Look of Love — Follies Director
• 201150 Greatest Harry Potter Moments — Arthur Weasley (archive footage)
• 2011Albert Nobbs — Sean Casey
• Fern
• 2011Frankenstein's Wedding... Live in Leeds — Alphonse Frankenstein
• 2011Harry Potter and the Deathly Hallows: Part 2 — Arthur Weasley
• 2010Harry Potter and the Deathly Hallows: Part 1 — Arthur Weasley
• Little Crackers — Father Christmas
• The Indian Doctor — Richard Sharpe
• Being Human — Regus
• 2009Harry Potter and the Half-Blood Prince — Arthur Weasley
• A Room with a View — Mr Beebe
• Merlin — The Goblin (voice)
• Sense and Sensibility — Sir John Middleton
• 2007A Room with a View — Mr Beebe
• 2007Harry Potter and the Order of the Phoenix — Arthur Weasley
• 2007Stardust — Billy
• Saxondale — Deggsy
• 2006Viva Blackpool — Tommy Vesty
• 2005A Cock and Bull Story — Ingoldsby
• Doctor Who — Brian Williams
• 2005Harry Potter and the Goblet of Fire — Arthur Weasley
• The Rotters' Club — Sam Chase
• Agatha Christie's Marple — Commander Peters
• 2004Agent Cody Banks 2: Destination London — Inspector Crescent
• Carrie & Barry — Kirk
• 2004Harry Potter and the Prisoner of Azkaban — Arthur Weasley
• Hustle — Dale Ridley
• New Tricks — David Beaumont
• 2004The Heart of Me — Man
• Star — Mr Fisher
• 2003The Fast Show: The Farewell Tour — Various
• 2002Anita and Me — The Reverend 'Uncle' Alan
• 2002Dick Whittington: The ITV Pantomime — King Rat
• 2002Harry Potter and the Chamber of Secrets — Arthur Weasley
• Industrial Revelations
• Shackleton — Dudley Docker
• 2002The Final Curtain — Declan Farrell
• 2001Combat Sheep — Moose (voice)
• 2001Exit Wounds — Cop
• Fun at the Funeral Parlour
• Happiness
• 2001High Heels and Low Lifes — Tremaine
• Jumpers for Goalposts — Tommy Stein
• 2001Second Star to the Left — Duke (voice)
• Gormenghast — Professor Perch
• 2000Happy Birthday Shakespeare — Ted
• The Strangerers — Cadet Flynn
• 2000Whatever Happened to Harold Smith? — Roland Thornton
• 1999Hunting Venus — Peter
• 1999The Fast Show: You Ain’t Seen These, Right? — Writer
• Comedy Lab — Mr. Anderson
• 1998Shakespeare in Love — Wabash
• 1998Ted & Ralph — Confirmed Bachelor
• 1998The Fast Show Live
• Midsomer Murders — Pat Everett
• 1997The Borrowers — Exterminator Jeff
• 1996101 Dalmatians — Horace
• 1995The Big Game — Tommy Hollis
• 99-1 — John Samms
• 1994Fever — Jukebox Man
• Harry Enfield and Chums — Husband on Holiday
• 1994Prince of Jutland — Aslak
• The Fast Show — Various Characters, Writer
• Chef — Policeman 2
• Peak Practice — Roland Grogan
• The Smell of Reeves and Mortimer
• Bunch Of Five — Tim
• Bottom — Boris
• Kinsey — Danny
• Merlin of the Crystal Cave — Cerdic
• Great Expectations — Mr. Trabb's Son
• KYTV
• Alexei Sayle's Stuff
• 1988Coppers
• Red Dwarf — Olaf Petersen
• The Storyteller — Fearnot's Brother
• 1988The Storyteller: Fearnot — Fearnot's Brother
• 1988Tumbledown — Lumpy
• Casualty — Des Jones
• 1982Privileged — Wilf
• Lead Heads
• Mark Williams' Big Bangs
• The Dudley Bug — Roderick the Palaeontologist

Appearances as themselves (13)

• Fantastic Friends — Self
• 2022Harry Potter 20th Anniversary: Return to Hogwarts — Self
• 2017Harry Potter: A History Of Magic — Himself
• Born Naughty? — Self - Narrator (voice)
• 2011When Harry Left Hogwarts — Self
• 2009Steve Coogan: The Inside Story — Self
• 2006Saxondale: On The Road — Self
• The One Show — Self
• The World's Strangest UFO Stories — Self - Narrator (voice)
• Mark Williams On The Rails — Self - Presenter
• Loose Women — Self
• 1999Suit You Sir! The Inside Leg Of The Fast Show — Self
• Top of the Pops — Self - Host