The Secret is a 2016 Northern Irish ITV mini-series based on Let This Be Our Secret, Belfast journalist Deric Henderson's account of the double murder of Lesley Howell and Constable Trevor Buchanan, whose bodies were discovered in a fume-filled car in the garage of a property in Castlerock, County Londonderry, in Northern Ireland in May 1991.

The drama stars James Nesbitt as killer dentist Colin Howell, is written by BAFTA-winning writer Stuart Urban and is directed by Nick Murphy. The producer is Jonathan Curling, and the executive producers are Hat Trick Productions' Mark Redhead and Stuart Urban.

It was broadcast from 29 April to 20 May 2016 in four episodes. The production was criticised by Howell's daughter, for the portrayal of her mother, and for 'exploiting a tragedy'. The drama was BAFTA nominated as Best Drama Miniseries. It won the Royal Television Society award for Best Drama, Northern Ireland and was nominated at The Broadcast Awards as Best Drama.