Dark Heart is a British television crime drama series, based on the Will Wagstaffe novels by writer Adam Creed, that first broadcast on 9 November 2016. The series stars Tom Riley as DI Will Wagstaffe, a police detective haunted by the unsolved double murder of his parents when he was just sixteen years old. A single feature-length pilot, based on the novel Suffer the Children, was written by Chris Lang and directed by Colin Teague. It first broadcast on ITV Encore on 9 November 2016. The initial pilot co-stars Kobna Holdbrook-Smith, Tom Brooke, Anjli Mohindra, Charlotte Riley and Miranda Raison.

Following strong audience reception, a series of six hour-long episodes was commissioned in December 2017, with filming taking place in Spring 2018. The series consists of four newly-written episodes alongside the pilot, which has been re-edited, with some scenes re-shot, to form the first two episodes of the series. Lang returned to pen the four new episodes; including two which were co-written by Ben Harris. Teague returned as director.

Jason Maza, Michele Austin, Alex Carter and Gregg Chillin joined the cast following the departures of Brooke and Holdbrook-Smith, who was unable to return to the series because of other filming commitments. Due to the closure of ITV Encore in March 2018, the series transmitted on ITV, alongside a number of other projects originally set for broadcast on Encore. The series began broadcasting on 31 October 2018, with episodes shown on Wednesdays and Thursdays at 9:00 pm.