His roles have included Albert Blithe in Band of Brothers (2001), Danny Blue in Hustle (2003-2007), Dougie Raymond in The Vice, Dominic Foy in State of Play, Rick in Mad Dogs (2011-2013), the Comte de Rochefort in The Musketeers (2015), the Gentleman in Jonathan Strange & Mr Norrell (2015), and Piet Van Der Valk in TV series Van Der Valk (2020).

[2] He studied drama at the East 15 Acting School in Loughton, Essex, but left without graduating after being asked to play "the colour orange".

[6] The same year, he starred as Ray Say in a West End revival of The Rise and Fall of Little Voice alongside Diana Vickers and Lesley Sharp.

[4] To promote the play, he wrote a series of articles for The Guardian, titled "Marc Warren's Little Voice diary",[7] and appeared on The One Show.

[10] He starred in the 1995 British drama film Boston Kickout,[4] and played immortal Morgan D'Estaing in the season four Highlander episode "Double Jeopardy" in 1996.

[11] He played Police Constable Dougie Raymond in the British television series The Vice,[11] and Albert Blithe in HBO's 2001 miniseries Band of Brothers.

The same month, he played Count Dracula in a new adaptation of Bram Stoker's classic novel, produced by ITV Productions for BBC Wales.

[15] The following year, he initiated and starred in a new Sky One production, Mad Dogs (alongside Max Beesley, Philip Glenister and John Simm), which eventually ran to fourteen episodes over four series.

That same year, he joined the cast of the American drama The Good Wife in the recurring role of Kalinda Sharma's estranged husband.