Comedy actor. Born in Dennistoun (Glasgow), Kiernan was educated at Whitehill Secondary School. He trained as a tailor, worked as a barman at the University of Glasgow and travelled the world as a marketing executive. Kiernan is known as an effective mimic and has developed a series of characters through his noted BBC Scotland TV series Chewin' the Fat and Still Game. He has also regularly broadcast for BBC Radio 4 and Radio Scotland, as well as having worked extensively in theatre. His play Don't Start Me won an award at the Edinburgh Festival Fringe (1995).
He has also appeared in films, including minor roles in Carla's Song (1996), with Robert Carlyle, Complicity (2000), from the novel by Iain Banks (b.1954), and the Gang's of New York (2002).
