In 1984, he won the Laurence Olivier Award for Best Actor in a Musical playing John Tallentire in Howard Goodall and Melvyn Bragg’s The Hired Man at the Astoria Theatre, London.
Hamp in For King and Country (Greenwich Theatre), Working Class Hero, The Hired Man, Venetian Twins, (Nuffield, Southampton).
Mephistopheles in Doctor Faustus, Roderigo in Othello, Captain Plume in The Recruiting Officer and Lieutenant Clark in Our Country's Good by Timberlake Wertenbaker (Swan, Worcester).
His TV appearances include Graham Carpenter in Hollyoaks (for two years), Keith Nicholl in two series of The Manageress for Channel 4, Mr Christian in Tripper's Day (revived for two series as Slinger's Day) for ITV, Heartbeat, Kavanagh QC, Kiss Me Kate, Eleven Men Against Eleven, Underworld, Drop The Dead Donkey, Dream Team, Home is the Sailor, Anna Lee, Class Act, Doctors, Casualty, The Bill and Crossroads.
Clarkson performed as Dr Dillamond in the musical Wicked at the Apollo Theatre, Victoria, London until 25 October 2014, and also understudied the Wizard of Oz.