Harris was born in Bethnal Green, London, but grew up in Lowestoft, Suffolk. He attended Denes High School, now the Ormiston Denes Academy in Lowestoft, Suffolk. At 23, he moved to London to train at the Drama Centre London from 1989 to 1992.
Harris played the main cast role of Thomas the Disciple, and later Thomas the Apostle in the 1999 biblical, historical, drama television film version of Jesus. Throughout the film, Thomas struggled violently with his unbelief in anything he could not see, touch, hear, nor know until the resurrection of Jesus when his hand had been placed within the wounds of Jesus. At that point, faith came to Thomas the Disciple and Jesus became the "Lord and God" of Thomas the Apostle. His notable roles include that of Joy Division's lead singer Ian Curtis in Michael Winterbottom's 2002 film, 24 Hour Party People and as Steven in the film short, True Love (Once Removed), directed by Kevin Thomas. The film won Best Short Film at both the Palm Springs and Houston Film Festivals, was selected for the Clermont-Ferrand, London Raindance and Los Angeles Short Film festivals and also qualified for an Oscar nomination in 2004.
Harris also played Nick Sidney in the 2005 mockumentary, Brothers of the Head, directed by Keith Fulton and Louis Pepe. In 2007, he appeared in his first feature film lead role as Eddie in Saxon, directed by Greg Loftin. In 2009, he played Stretch in Harry Brown, directed by Daniel Barber.
Harris' television credits include serial killer Ian Brady, on ITV1's television mini-series, See No Evil: The Moors Murders (2006), the 2007 television film Wedding Belles, Channel 4's drama series Cape Wrath (Meadowlands in the United States) as Gordon Ormond and the BBC series Ashes to Ashes as Arthur Layton.
In 2007, he appeared in a video for Mark Ronson's "Stop Me".
In 2009, he played corrupt Detective Inspector Bob Craven in Channel 4's critically acclaimed Red Riding trilogy and as Photographer Anton Blair in Dean Cavanagh's comedy series, Svengali.
From 2011-2013, Harris appeared as the Assassin Micheletto in The Borgias, a series created by Neil Jordan. In 2013, he starred as Stephen Morton in the Channel 4 drama Southcliffe, for which Harris would win a British Academy of Film and Television Arts award for Best Actor in 2014. He also played Joss Merlyn in the poorly received BBC adaptation of Jamaica Inn, which became a subject of controversy and made national news over its mumbling cast and other sound problems.
In 2012, Harris appeared in London-based music group Barbarossa's video short, Battles, directed by Montserrat Lombard. Harris and Lombard have been working on the screen play for a film short, White as well as a script for a feature-length film, Imager. He will play the lead in the film short with Lombard directing once again.
In 2014, Harris played Mick Santino in Deliver Us From Evil (2014), directed by Scott Derrickson and based upon the 2001 novel "Beware the Night" by Ralph Sarchie and Lisa Collier Cool. He was cast by Derrickson for the film, without an interview, based upon the Director having seen the actor's performance in Harry Brown. That same year, he appeared as Gene Womack in Guy Myhill's The Goob. Myhill previously directed Harris in two film shorts, Two Halftimes to Hell (1997) and The Fabulous Bilsons (2001). Harris finishes the year with his performances as Captain Sandy Browning in the critically acclaimed '71, directed by Yann Demange, for which he earned a British Independent Film Award nomination for Best Supporting Actor and as Campbell in Serena (2014), directed by Susanne Bier.
In 2015, Harris appeared as Solomon Lane in Mission: Impossible – Rogue Nation, directed by Christopher McQuarrie and as Macduff in Justin Kurzel's Macbeth. His next project, Trespass Against Us, was released in 2016.
Harris filmed Possum in 2016, a film by Matthew Holness, in which he plays the main character. He has wrapped filming in °Mission: Impossible – Fallout°.
