The performing arts at Saint James School fosters well rounded learners and provides a structure for students to develop interdisciplinary skills while engaging in the arts. The Fine Arts Department produces three main stage productions each year in order to enhance students' experience in a project based learning environment. Students are encouraged to claim agency in every realm of theater making. They may explore acting, dance, choreography, lighting and set design, direction, and stage management. The performing arts curriculum begins during the second form, performing Shakespeare's text, playing with improvisation, and completing scene studies. By their fifth form year students have the opportunity to write, direct, and produce their own work.

The Kellam Auditorium is a 264-seat theater that affords young actors and technicians a colorful hands-on experience and an opportunity to bring theater to life.