Derek Riddell (born 11 January 1967) is a Scottish television and theatre actor. He is best known for the portrayal of Dr. Jamie Patterson in the Channel 4 television series No Angels. He has also guest starred in Doctor Who, Ugly Betty, Silent Witness, Waterloo Road, and Shetland (2013–).

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.

After finishing drama school, Riddell was cast in BBC Scotland production Strathblair and guest-starred in a number of popular TV shows such as Taggart, Casualty and The Bill. His big break came in the critically acclaimed Channel 4 series The Book Group and comedy drama No Angels. In addition to his television work he also regularly works in theatre productions.