Casady's theatre program begins in Middle Division, with drama offered as an elective to students in 7th and 8th grade. There is also an annual performance in Middle Division, with recent examples being Suessical Jr. and School House Rock Jr.
In Upper Division, the theatre program expands to include acting and technical theater which includes considerations like lighting, set design and audio systems. An independent study in theater is also available. Upper Division also includes two annual performances: one music and one play, with recent examples including Damn Yankees, A Midsummer Night's Dream, Peter and the StarCatcher, and 12 Angry Jurors.