Parkside Collegiate Institute is the largest secondary school in St. Thomas, serving approximately 1,000 students. Opened in 1967, the large school campus backs on to Lake Margaret and Pinafore Park.
Parkside is a large composite school offering educational pathways to all students, including French Immersion. There is a broad and well supported extracurricular program, including sports, the arts and clubs. Parkside also has a Community Living Centre that serves the needs of developmentally challenged pupils.