A (usually high school) student who performs in plays or does technical theatre work. Originally a term of derision (see definitions below), "theatre geek" has now been co-opted by theatre geeks.

One who fills two requirements:
1. Participates in plays and musicals, either by acting, stage managing, joining tech crew or doing other technical work.
2. Enjoys the viewing and reading of plays and musicals.

This is not to be confused with a theatre snob, who only fills the second requirement.

A theatre geek is a person who is in theatre, knows everything about theatre, and is one of the most awesome kinds of people to live.

a theatre major that thinks she/he is better than everyone else who isn't a theatre major