A British author, cartoonist, comics scriptwriter, and television screenwriter.
Riley has written several best-selling cartoon books, The Book of Bunny Suicides, Return of the Bunny Suicides, The Bumper Book of Bunny Suicides, Dawn of the Bunny Suicides, Great Lies To Tell Small Kids, Loads More Lies to Tell Small Kids, and Selfish Pigs. From 2002 until February 2010 he drew a weekly comic strip called Roasted in The Observer Magazine. D.I.Y. Dentistry was released in October 2008 in hardback. 'Lucky Heather', is his self-published comic.
With Kevin Cecil, his long time friend and he created and wrote the sitcoms The Great Outdoors, Hyperdrive and Slacker Cats for the ABC Family Channel. Their other television work includes Black Books, Robbie the Reindeer, Little Britain, Trigger Happy TV, So Graham Norton, Smack the Pony, The Armando Iannucci Shows and Spitting Image. The Radio Four panel game they wrote with Jon Holmes and Tony Roche, The 99p Challenge, ran for five series from 2000.
They have written for the forthcoming Miramax animated feature Gnomeo and Juliet, and did an uncredited rewrite for Tim Burton's Corpse Bride.