Simon is best known for his acclaimed interpretation of Jean Valjean in Cameron Mackintosh's new production of Les Miserables for which he received the 2015 Helpmann award for Best Male Actor in a Musical.

His  stage credits include Jolson, Shout, Mamma Mia (Helpmann Award nomination), Eureka, Chess (Greenroom Award nomination) Love Never Dies (Helpmann and Sydney Theatre Award nominations) and Hipbone Sticking Out (BighART). He appeared for the Sydney Theatre Company in Harbour and The Republic of Myopia and was a member of the original cast of Rupert for the Melbourne Theatre Company, which he also toured to the Kennedy Center in Washington. Simon’s UK credits include The Far Pavilions (West End; for which he received a Whatsonstage Award nomination), Imagine This (West End), Three Sides, The Silver Lake, Certified Male (Edinburgh Festival), Shoes (Sadler’s Wells) and Southwark Fair (Royal National Theatre) directed by Sir Nicholas Hytner.

Simon’s film and television credits in Australia include City Homicide, Blue Heelers and SeaChange. In the UK, he played a regular role in EastEnders and was a member of the principal cast of Kombat (BBC2) directed by Monty Python member Terry Jones. Simon also appeared in the feature film My Life In Ruins.