- Bunker
2026 Simon
- Mission: Impossible - The Final Reckoning
2025 Angstrom
- The Fantastic 4: First Steps
2025 Ted Gilbert
- Marvel Studios' The Fantastic Four: First Steps - World Premiere
2025 Ted Gilbert (archive footage) (uncredited)
- The Painting & The Statue
2025 Old Lord/Butler 'Smith'/Dancing Man/Old Lord 'Johnny'
- Bookish
2025 Writer
- A Ghost Story for Christmas: The Room in the Tower
2025 Director
- National Theatre Live: The Motive and the Cue
2024 Sir John Gielgud
- 3 Body Problem
2024 Isaac Newton
- Time Bandits
2024 Earl of Sandwich
- Moonflower Murders
2024 Frank Parris / Oscar Berlin
- A Ghost Story For Christmas: Woman of Stone
2024 Director
- The Hound of the Baskervilles
2023 Sherlock Holmes
- Nolly
2023 Larry Grayson
- Juice
2023 George
- A Ghost Story for Christmas: Lot No. 249
2023 Director
- A Christmas Carol: A Ghost Story
2022 Adaptation
- Operation Mincemeat
2022 Ivor Montazac
- The Road Dance
2022 Doctor MacLean
- Inside Classical
2022 Sherlock Holmes
- A Ghost Story for Christmas: Count Magnus
2022 Director
- Memento Mori
2021 Henry Huxley
- A Silent Imprisonment
2021 Mr Murphy
- The Amazing Mr. Blunden
2021 Director
- Locked Down
2021 Donald
- A Ghost Story for Christmas: The Mezzotint
2021 Director
- The Father
2020 The Man
- In Search of Dracula
2020 Himself - Presenter
- Dracula
2020 Writer
- Brexit: The Uncivil War
2019 Peter Mandelson (voice)
- Doctor Who and the Third Man
2019 Himself
- Good Omens
2019 Mr. Harmony
- Martin's Close
2019 Director
- The Dead Room
2018 Director
- The Favourite
2018 Lord Marlborough
- Christopher Robin
2018 Giles Winslow
- The Mercy
2018 Ronald Hall
- National Theatre Live: The Madness of George III
2018 George III
- Mark Gatiss on John Minton: The Lost Man of British Art
2018 Himself - Presenter
- The League of Gentlemen - Live Again!
2018 Writer
- Sally4Ever
2018 Doctor
- Against the Law
2017 Dr. Landers
- Doctor Who: Twice Upon a Time
2017 The Captain
- Gunpowder
2017 Sir Robert Cecil
- Taboo
2017 Prince Regent
- Queers.
2017 Director
- Dad's Army
2016 Colonel Theakes
- Sherlock: The Abominable Bride
2016 Writer
- Our Kind of Traitor
2016 Billy Matlock
- Denial
2016 Professor Robert Jan van Pelt
- Absolutely Fabulous: The Movie
2016 Joel
- Mark Gatiss: A Study in Sherlock
2016 Himself
- Victor Frankenstein
2015 Dettweiler
- Coalition
2015 Peter Mandelson
- The Vote
2015 Steven Crosswell
- Premium Bond with Mark Gatiss and Matthew Sweet
2015 Himself
- London Spy
2015 Rich
- Thunderbirds Are Go!
2015 Dr. Quentin Questa (voice)
- Wolf Hall
2015 Stephen Gardiner
- Unlocking Sherlock
2014 Himself / Mark Gatiss
- National Theatre Live: Coriolanus
2014 Menenius Agrippa
- Mapp and Lucia
2014 Major Benjamin 'Benjy' Flint
- Inside No. 9
2014 Callum
- The Real History of Science Fiction
2014 Himself - Narrator (voice)
- M.R. James: Ghost Writer
2013 Writer
- Dr. Forever!
2013 Himself
- Psychobitches
2013 Joan Crawford
- An Adventure in Space and Time
2013 Writer
- The Tractate Middoth
2013 Director
- Sherlock: Many Happy Returns
2013 Writer
- Doctor Who: The Great Detective
2012 Narrator
- Horror Europa with Mark Gatiss
2012 Writer
- Playhouse Presents
2012 Joan Crawford
- Cleaning Up
2011 Mr Jackson
- The Crimson Petal and the White
2011 Henry Rackham Junior
- Game of Thrones
2011 Tycho Nestoris
- The First Men in the Moon
2010 Screenplay
- Worried About the Boy
2010 Malcolm McLaren
- Unlocking Sherlock
2010 Himself
- Sherlock
2010 Writer
- A History of Horror
2010 Writer
- Ghosts in the Machine
2009 Himself
- Spanish Flu: The Forgotten Fallen
2009 Ernest Dunks
- New Town
2009 Duff Purves
- Being Human
2009 Mr. Snow
- Clone
2008 Colonel Black
- Crooked House
2008 Writer
- Sense and Sensibility
2008 John Dashwood
- Consenting Adults
2007 PC Butcher
- The Worst Journey in the World
2007 Writer
- Grindhouse
2007 (segment "Don't") (uncredited)
- Jekyll
2007 Robert Louis Stevenson
- Derren Brown: Trick or Treat
2007 Himself
- A New Body at Last
2007 Thanks
- The League of Gentlemen Are Behind You
2006 Author
- The Wind in the Willows
2006 Rat
- Starter for 10
2006 Bamber Gascoigne
- Fear of Fanny
2006 Johnnie Cradock
- Wallace & Gromit: The Curse of the Were-Rabbit
2005 Miss Blight (voice)
- The Quatermass Experiment
2005 John Paterson
- The League of Gentlemen's Apocalypse
2005 Writer
- Match Point
2005 Ping-Pong Player
- The Hitchhiker's Guide to the Galaxy
2005 Additional Vogon Voices
- Return of the Goodies
2005 Himself
- Doctor Who
2005 Writer
- Funland
2005 Ambrose Chapfel
- Agatha Christie: A Life in Pictures
2004 Kenyon
- Sex Lives of the Potato Men
2004 Jeremy
- Shaun of the Dead
2004 Radio Presenter With 'Spaceship' Theory / Wildlife voiceover (voice) (uncredited)
- Global Conspiracy?
2004 Writer
- Catterick
2004 Peter
- Nighty Night
2004 Glenn Bulb
- Agatha Christie's Marple
2004 Ronald Hawes
- Bright Young Things
2003 House Agent
- Little Britain
2003
- The Cicerones
2002 John Trant
- Robbie the Reindeer: Legend of the Lost Tribe
2002 Viking (voice)
- Surrealissimo: The Trial of Salvador Dali
2002 Louis Aragon
- Footballers' Wives
2002 Teddy - Agent
- Birthday Girl
2001 Porter
- The League of Gentlemen: Live at Drury Lane
2001 Writer
- Dr Terrible's House of Horrible
2001 Hang Man Chang
- Randall & Hopkirk (Deceased)
2000 Writer
- The Web of Caves
1999 Writer
- The Kidnappers
1999 Writer
- The Pitch of Fear
1999 Writer
- Spaced
1999 Agent
- The League of Gentlemen
1999 Writer
- In the Red
1998 Junior Detective
- Midsomer Murders
1997 Rev Giles Shawcross
- PROBE: Unnatural Selection
1996 Writer
- PROBE: Ghosts of Winterborne
1996 Writer
- Highgate House of Horror
1995 Director
- PROBE: The Devil of Winterborne
1995 Writer
- PROBE: The Zero Imperative
1994 Writer
- The Dwelling Place
1994 Bowmer
- Harry
1993 Diner Manager
- Agatha Christie's Poirot
1989 Screenplay
- A Ghost Story for Christmas
1971 Director
- A Ticket Too Far
Marshall
- Cuddle
Paul
