David Llewellyn (born 1978), is a Welsh novelist and script writer. He grew up in Pontypool and graduated from Dartington College of Arts in 2000. His first novel, Eleven, was published by Seren Press in 2006. His second, , a spin-off from the BBC drama series Torchwood, was published in March 2008. Everything Is Sinister was published by Seren in May 2008, Ibrahim & Reenie in 2013 and A Simple Scale in 2018. A Simple Scale was shortlisted for the 2019 Polari Prize. In addition to writing novels, Llewellyn has written a number of audio plays for Big Finish Productions.