Derek Riddell (born 11 January 1967) is a Scottish television and theatre actor. He is best known for the portrayal of Richard Cawood in the BBC One television series Happy Valley. He is also known for Gentleman Jack, Industry and The Missing. He has guest-starred in Doctor Who, Ugly Betty, Silent Witness, Waterloo Road, and Shetland. Riddell was born in Glasgow, the son of teacher and former actress Hope Ross and former St Mirren and Berwick Rangers footballer Ian Riddell. He graduated from the University of Strathclyde with a degree in business, before training at the London Academy of Music and Dramatic Art, graduating in 1990.