Actor profile
Career and selected work
Mark Gatiss is an English actor, writer and director whose work frequently returns to mysteries, horror and the possibilities of television storytelling. His acting credits include the ensemble comedy The League of Gentlemen and Mycroft Holmes in Sherlock. Wolf Hall, Denial, The Favourite and The Father offer further screen appearances in markedly different settings.
It is helpful to keep his professional roles separate. Being familiar with Gatiss as a writer does not mean he wrote the production in which you are watching him act. In Moonflower Murders he performs within Anthony Horowitz’s adaptation. For a short exploration of his acting, pair one of the television roles with a film from the list below. Notice how the form changes the information available to the viewer: a continuing character can accumulate associations across episodes, while a film may establish a relationship in only a few scenes. That contrast is useful preparation for the compact character introductions of a murder mystery.
Six roles to explore
- The League of Gentlemen (1999–2002) — various roles.
- Sherlock (2010–2017) — Mycroft Holmes.
- Wolf Hall (2015) — Stephen Gardiner.
- Denial (2016) — Robert Jan van Pelt.
- The Favourite (2018) — John Churchill.
- The Father (2020) — the man.
In the Susan Ryeland adaptations
Gatiss plays Frank Parris in Moonflower’s contemporary history and Oscar Berlin in Alan Conway’s novel. Frank’s stay at Branlow Hall is part of the story Susan must reconstruct. Oskar belongs to the separate mystery she reads. The same actor makes a connection visible without turning the two men into a single character. Since the modern investigation concerns events remembered and described by others, keep track of who supplies an account of Frank. Compare that with what the novel actually shows about Oskar, rather than assuming every resemblance gives a complete explanation.
Where to watch and explore next
Explore the Susan Ryeland episodes. Check local streaming services for other roles before subscribing. Use the year and character to identify the right production.
The character links below lead into the story guides. Endings stay in closed sections. Open them when you are ready for spoilers. Watching for the first time? Follow the episodes in order. Rewatching? Compare the performances across the two worlds.
Characters played
Stage and radio
Gatiss played John Gielgud in The Motive and the Cue at the National Theatre in 2023. His performance in Three Days in the Country earned the 2016 Olivier Award for a supporting role. On radio, he played Professor Nebulous in Nebulous for BBC Radio 4 in 2005; his writing and performing credits also include On the Town with the League of Gentlemen in 1997.
Source: PBJ Management: Mark Gatiss. Checked 19 October 2026.
Read or listen to the book
Moonflower Murders (2020)
Anthony Horowitz’s novel behind the second television mystery.
Waterstones · print Audible · audiobookPaid links may earn commission, at no extra cost.


