Simon has worked on a wide range of shows as associate or resident director. His credits include ten productions of the smash-hit comedy Art (West End & UK tours), The Rocky Horror Show (West End & UK tours), the 50th Anniversary production of West Side Story (UK tour), Rent (West End), Simply Heavenly (West End), as well as seasons for D'Oyly Carte Opera Company and the Open Air Theatre, Regent's Park.

He was most recently associate director for the critically acclaimed End of the Rainbow, both in the West End and the UK tour. The show received four Olivier nominations and is about to embark on a U.S tour before transferring to Broadway later in 2012.