Dillane has worked frequently in television, professing himself to be "a little lost on stage at the moment." He joined the cast of Game of Thrones in 2011 as Stannis Baratheon, a major contender for the throne of the fictional realm of Westeros. While admitting he had not read the books on which the series is based, he commented that the show's appeal was due to "the storytelling, the extraordinary world that’s created and the way it reflects our actual world – a naked, ruthless pursuit of power in all its forms." In 2012 he also played Rupert Keel, head of the private security agency Byzantium, in the BBC drama series Hunted. The following year he went on to take the male lead, opposite Clémence Poésy, in the crime drama series The Tunnel, an Anglo-French remake of the Scandinavian The Bridge. Dillane, who had not seen the original series, plays Karl Roebuck, the laid-back, experienced British detective to Poésy's humourless French counterpart. His performance won him an International Emmy Award for Best Actor. In a second series in 2016, titled The Tunnel: Sabotage, he reprised his role alongside Poésy for a new case involving a deadly airliner crash in the English Channel.