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 School House Rock Jr. and Moana 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 Peter and the StarCatcher, 12 Angry Jurors, Mamma Mia, and Twelfth Night.