The school had a preparatory school called "Connor House" for pupils aged 4–11 until the end of the 2011–12 academic year. As is the case for many single-sex schools Bangor Grammar maintains close links with its sister single sex school in Bangor, Glenlola Collegiate. The two schools regularly participate in joint activities, most notably the Combined Cadet Force, which meets in an MoD-funded, purpose-built site on Bangor Grammar's campus; the two Scripture Union Societies which hold joint meetings and activities; and the two drama departments, which collaborate on student productions. Former Bangor Grammar students have represented Northern Ireland, Ireland, Great Britain and Europe at international level in a number of sports.