General terms:
* Theatre enthusiast: This is a straightforward and common term.
* Theatre lover: Similar to enthusiast, but perhaps with a stronger emotional connection.
* Theatre aficionado: Implies a deep knowledge and appreciation of theatre.
* Thespian: This word is often used to describe someone who is involved in theatre, but it can also be used to describe someone who loves it.
More specific terms:
* Stage door Johnny/Jane: This term refers to someone who is obsessed with theatre and often hangs around backstage.
* Playgoer: This term refers specifically to someone who attends theatre performances.
* Drama buff: This term is more informal and suggests a keen interest in theatre.
Ultimately, the best word to use depends on the context and the level of enthusiasm you want to convey.