Clifford trained at the Guildhall School of Music & Drama, and graduated early to make his debut at the Royal Shakespeare Company, in Julius Caesar and The Two Gentlemen of Verona, in Stratford-upon-Avon and also toured in the United States.
Clifford portrayed Tony Anderson, opposite actor Jack Shepherd, in the play Chasing the Moment at the Arcola Theatre.
Clifford recently finished performing at the National Theatre as the co-lead in a new play by the actor/playwright Kwame Kwei-Armah called Statement of Regret.
He has recently finished playing 'Eilif' in Mother Courage and Her Children at the National Theatre opposite Fiona Shaw directed by Deborah Warner.
2014, The Events, Actors Touring Company, as The Boy 2010, Sex & Drugs & Rock & Roll, (Upcoming Film) 2008, Statement of Regret, National Theatre as Adrian Mackenzie 2007, Shoot on Sight, as Elijah, Film 2007, The Bill, as Tyrone Brooks, TV Drama 2007, Roman’s Empire, as Frobisher, BBC TV series Chasing the Moment, 2007, Arcola theatre as Tony Anderson, Best Play Timeout Critics Choice Award The Changeling, 2006, Cheek by Jowl stage play, Barbican/European Tour as Tomazo, Best International play El Mundo & El Pais Awards Spain Julius Caesar, 2005, Royal Shakespeare Company, as Octavius Caesar