(2005) Wallace & Gromit: The Curse of the Were-Rabbit

as Miss Blight (voice)

(2001) Birthday Girl

as Porter

(2000) The League of Gentlemen - Yule Never Leave!

as ---

(2021) Memento Mori

as Henry Huxley

(1997) Stranger Than Fiction 3: Acting Up

as ---

(2006) The League of Gentlemen Are Behind You

as Hilary Briss / Mickey Michaels / Val Denton / Les McQueen / Lance Longthorne / Alvin Steele / Phil Proctor / Mrs Beasley / Mick McNamara / Neds / Lotte Lipp / Brian Morgan / Dr Chinnery / Iris Krell / Bobbin

(2021) A Silent Imprisonment

as Mr Murphy

(2004) Agatha Christie: A Life in Pictures

as Kenyon

(2021) The Amazing Mr. Blunden

as Mr. Wickens

(2020) Tales of the Uncanny

as Self

(2009) Ghosts in the Machine

as Himself

(2005) The Quatermass Experiment

as John Paterson

(2010) The First Men in the Moon

as Cavor

(2002) The Cicerones

as John Trant

(2009) Spanish Flu: The Forgotten Fallen

as Ernest Dunks

(2004) Spaced: Skip to the End

as Self

(2014) Unlocking Sherlock

as Himself / Mark Gatiss

(2002) Robbie the Reindeer: Legend of the Lost Tribe

as Viking (voice)

(2023) Hammer A.D. 2023

as Self

(2014) National Theatre Live: Coriolanus

as Menenius Agrippa

(2010) Worried About the Boy

as Malcolm McLaren

(2006) Starter for 10

as Bamber Gascoigne

(2006) The Wind in the Willows

as Rat

(2006) Fear of Fanny

as Johnnie Cradock

(2005) The League of Gentlemen's Apocalypse

as Various Characters

(2013) M.R. James: Ghost Writer

as Presenter

(2004) Sex Lives of the Potato Men

as Jeremy

(2015) Victor Frankenstein

as Dettweiler

(2014) 50 Years of BBC Two Comedy

as Self

(2012) Doctor Who: The Great Detective

as Narrator

(2023) The Hound of the Baskervilles

as Sherlock Holmes

(2022) A Christmas Carol: A Ghost Story

as Jacob Marley

(2012) Horror Europa with Mark Gatiss

as Self - Host

(2018) The Dead Room

as Radio Announcer (voice)

(2003) The Kneale Tapes

as Self

(2024) National Theatre Live: The Motive and the Cue

as Sir John Gielgud

(2015) Coalition

as Peter Mandelson

(2015) The Vote

as Steven Crosswell

(1994) The Zero Imperative

as Dr. William Bruffin

(1996) Unnatural Selection

as Mr. Emerson

(2011) Cleaning Up

as Mr Jackson

(2022) Peter Davison: Uncut!

as Self

(2016) Dad's Army

as Colonel Theakes

(2005) Match Point

as Ping-Pong Player

(2003) Bright Young Things

as House Agent

(2016) Sherlock: The Abominable Bride

as Mycroft Holmes

(2007) Consenting Adults

as PC Butcher

(2016) Our Kind of Traitor

as Billy Matlock

(2005) Doctor Who: A New Dimension

as Self

(2016) Denial

as Professor Robert Jan van der Pelt

(2016) Absolutely Fabulous: The Movie

as Joel

(2005) The Hitchhiker's Guide to the Galaxy

as Additional Vogon Voices

(2012) The Real Sherlock Holmes

as Self

(2007) The Worst Journey in the World

as Apsley Cherry-Garrard

(2005) Return of the Goodies

as Himself

(2001) The League of Gentlemen: Live at Drury Lane

as various

(2017) Against the Law

as Dr. Landers

(2002) Surrealissimo: The Trial of Salvador Dali

as Louis Aragon

(1996) Bidding Adieu: A Video Diary

as Self - Interviewer

(1995) Stranger than Fiction 2: From Script to Screen

as ---

(2018) The Favourite

as Lord Marlborough

(2015) Premium Bond with Mark Gatiss and Matthew Sweet

as Himself

(2007) Don't

as Roddy McDowel

(2017) Doctor Who: Twice Upon a Time

as The Captain

(2018) Christopher Robin

as Giles Winslow

(2016) Mark Gatiss: A Study in Sherlock

as Himself

(2018) The Mercy

as Ronald Hall

(2018) National Theatre Live: The Madness of George III

as George III

(2017) Mars: a Traveller's Guide

as Narrator

(2018) Mark Gatiss on John Minton: The Lost Man of British Art

as Himself - Presenter

(2004) Shaun of the Dead

as Radio Presenter With 'Spaceship' Theory / Wildlife voiceover (voice) (uncredited)

(2004) Global Conspiracy?

as Terry Scanlon

(2018) The League of Gentlemen - Live Again!

as Various Characters

(2020) The Father

as The Man

(2019) Brexit: The Uncivil War

as Peter Mandelson (voice)

(2009) New Town

as Duff Purves

(2020) In Search of Dracula

as Himself - Presenter

(2022) Operation Mincemeat

as Ivor Montazac

(2013) Doctor Who Live: The Next Doctor

as Self

(1999) The Kidnappers

as Mark

(1999) The Pitch of Fear

as Mr. Borusa

(1999) The Web of Caves

as The Doctor

(2020) Scandal & Beauty: Mark Gatiss on Aubrey Beardsley

as Himself

(2021) Locked Down

as Donald

(2019) Doctor Who and the Third Man

as Himself

(2006) The League of Gentlemen Are Behind You!

as ---

(2012) Back to Black: The Making of Dracula Prince of Darkness

as Self - Actor and Writer

(2023) Mission: Impossible - Dead Reckoning Part One

as NSA

(2015) Release the Hound!

as Self

(2021) The Sparks Brothers

as Self

(1995) Highgate House of Horror

as Mr Banham

(1995) The Devil of Winterborne

as Georgie

(2007) Grindhouse

as (segment "Don't") (uncredited)

(2020) Cold War Steve Meets the Outside World

as Self

(2022) The Road Dance

as Doctor MacLean

(2010) Unlocking Sherlock

as Himself

(2005) Don't Crash: The Documentary of the Making of the Movie of the Book of the Radio Series of 'The Hitchhiker's Guide to the Galaxy'

as Self - The League of Gentlemen

(2025) Mission: Impossible - The Final Reckoning

as NSA

(2024) Inside No. 9: The Party's Over

as Self

(2014) Sherlock: His Last Vow

as Mycroft Holmes

(2014) How to Be Sherlock Holmes: The Many Faces of a Master Detective

as Self

(2007) Jekyll

as Robert Louis Stevenson

(1999) Spaced

as Agent

(2004) Nighty Night

as ---

(1998) This Morning with Richard Not Judy

as ---

(2005) Doctor Who Confidential

as ---

(2003) QI

as Self

(2001) Friday Night with Jonathan Ross

as Self

(1999) The League of Gentlemen

as ---

(2013) Dr. Forever!

as Himself

(2008) Only Connect

as Self - Contestant

(2000) Randall & Hopkirk (Deceased)

as ---

(2008) Sense and Sensibility

as John Dashwood

(2008) Clone

as Colonel Black

(2010) Sherlock

as Mycroft Holmes

(2008) Crooked House

as The Curator

(2009) Psychoville

as ---

(2010) A History of Horror

as Self - Presenter

(2005) Doctor Who

as Gantok

(2011) The Crimson Petal and the White

as Henry Rackham Junior

(1997) Midsomer Murders

as Rev Giles Shawcross

(2004) Who Do You Think You Are?

as Self

(2009) Horrible Histories

as ---

(2015) London Spy

as Rich

(2004) Catterick

as Peter

(2007) Derren Brown: Trick or Treat

as Himself

(2001) Dr. Terrible's House of Horrible

as Hang Man Chang

(1993) Harry

as Diner Manager

(1998) In the Red

as Junior Detective

(2003) Little Britain

as ---

(2010) Mid Morning Matters with Alan Partridge

as ---

(2005) Funland

as ---

(2005) Doctor Who

as Richard Lazarus

(2005) Doctor Who

as The Captain

(2009) Doctor Who Greatest Moments

as Self

(2014) Mapp and Lucia

as Major Benjamin 'Benjy' Flint

(2011) Game of Thrones

as Tycho Nestoris

(2004) Nighty Night

as Glenn Bulb

(2015) Thunderbirds Are Go!

as Dr. Quentin Questa (voice)

(2017) Gunpowder

as Sir Robert Cecil

(1994) The Dwelling Place

as Bowmer

(2014) Inside No. 9

as Callum

(2014) The Real History of Science Fiction

as Himself - Narrator (voice)

(2014) Doctor Who Extra

as Self

(2024) Moonflower Murders

as Frank Parris / Oscar Berlin

(2022) Inside Classical

as Sherlock Holmes

(2004) Agatha Christie's Marple

as Ronald Hawes

(2024) 3 Body Problem

as Isaac Newton

(2019) Good Omens

as Mr. Harmony

(2010) Sherlock

as Self

(2010) Sherlock

as Self / Mycroft Holmes

Bookish

as Gabriel Book

(2005) Doctor Who Confidential

as Narrator

(1989) Agatha Christie's Poirot

as Leonard Boynton

(2023) Nolly

as Larry Grayson

(2014) Inside No. 9

as Self

(2002) Footballers' Wives

as Teddy - Agent

(2024) Time Bandits

as Earl of Sandwich

(2024) Time Bandits

as Earl of Sandwich (voice)

(2020) Dracula

as Frank Renfield

(2015) Wolf Hall

as Stephen Gardiner

(2017) Taboo

as Prince Regent

(2009) Being Human

as Mr. Snow