- Dr Carter in June 1992 and February 1993
- An unnamed Court Usher in March 1998
- Peter Hartnell between September 2000 and September 2001
- Gerald in May 2010
- Charlie, a pawnbroker friend of Lewis Archer in November 2012
Having grown up in Bromley, he completed an engineering degree at Loughborough and then moved to Manchester where he worked in the transport industry for four years. He then trained as an actor at Manchester Polytechnic School of Theatre between 1988 and 1991.
Riley has also played minor roles in various other television series including Emmerdale, The Bill and Heartbeat.