He worked for three years in the Civil Service in Liverpool before training as an actor at the London Academy of Music and Dramatic Art.

At the Sheffield Crucible he appeared in Charley's Aunt and Absurd Person Singular then Victoria Wood's Good Fun (1980).

In 1996, Kelly appeared at the National Theatre in Helen Edmundson's adaptation of Leo Tolstoy's War and Peace.

[7] In 1998, Kelly appeared as George Spelvin in a concert version of Strike Up the Band at the Barbican in London and also was seen in an episode of the first series of Cold Feet, playing Algernon Gifford.

Also in 2004 he played two characters Harry Hawkswell and Stan Bickle in series 13 episode 22 of Heartbeat A Call to Arms.

Kelly starred in Jean-Paul Sartre's play Kean alongside Antony Sher at the Theatre Royal, Bath and in the West End in May 2007.

Kelly though did act in the Doctor Who audio dramas "The Holy Terror" and "Return to the Web Planet" by Big Finish Productions.

From May 2009, Kelly starred as the Wizard in the West End production of the musical Wicked,[8] replacing Desmond Barrit.

On 23 July 2010, Kelly guest starred as Martin in the sitcom My Family in the episode Desperately Stalking Susan.