The School's site at Hornsby covers over twenty hectares on a sloping, single campus. The Junior School, though autonomous, is located in the lower grounds of the school and shares the tranquil, spacious campus with the Middle and Senior Schools.

Barker College has excellent facilities including:

• a library which consolidates the School's unparalleled collection of print and non-print resources
• a superbly appointed and fully equipped Information Technology Centre
• the McCaskill Music Centre, containing private tuition studios, classrooms provided with computers for composition and aural skilling, a state-of-the-art recording studio, and a recital room
• three Drama performance spaces, including two spacious rehearsal rooms, a Drama Theatre with raked seating, and the School Hall, all equipped with industry-standard sound and lighting equipment
• the Centenary Design Centre with provision for individual studios and whole-class teaching in Design & Technology and Visual Arts including computer graphics, film-making and photography
• the Barker Foundation Science Centre, completed in 2000, containing ten teaching laboratories, four individual student laboratories and a 106-seat lecture theatre
• well appointed boarding houses
• extensive sporting fields, together with Tennis and Basketball courts, and an artificial surface for Hockey, Soccer, Netball, Athletics, Basketball, Volleyball and other games.
• a large gymnasium, fully equipped with weights and resistance training equipment, with an adjoining indoor Aquatic Centre