Glenn began his theatre career at the age of sixteen and has been working consistently since. His professional credits include Jolson - The Musical, We Will Rock You, Dr Zhivago, Pippin, Sweet Charity, Little Me, Eurobeat – Almost Eurovision, Monty Python's Spamalot, Mamma Mia!, Dirty Rotten Scoundrels and Jesus Christ Superstar. Glenn’s featured roles have included Aaron Schultz in Legally Blonde The Musical (GFO), Lumiere in Beauty & The Beast (ALG Productions & Melbourne Zoo), Frank Schultz in Show Boat (The Production Company), Calvin Berger in Calvin Berger - A Musical (MTC), Padre Perez in Man of La Mancha (Squabbalogic) and Escapologist/Magnus in Matilda (Royal Shakespeare Company/Louise Withers).
In 2012, Glenn was the recipient of the Rob Guest Endowment Award, and he was nominated as Best Supporting Actor In A Musical at the 2018 Green Room Awards for his portrayal of Cornelius Hackl in Hello Dolly! (The Production Company). More recently he appeared as Bob Crewe in Jersey Boys (New Theatricals) and Bobby in A Chorus Line (Darlinghurst Theatre).