The Belvedere Union enables past pupils of Belvedere College to maintain friendships made at school, to help our members who are in need and to provide opportunities for Old Belvederians to connect with each other . We do this by organising social, business and sporting events and also by supporting charities and other social justice activities in parallel with Belvedere College.

The Union is run by a voluntary committee who organise a range of different activities throughout the year which include the Union Dinner, the Belvedere Business Network Lunch, the Annual Retrete and the Annual mass for deceased past pupils.

The Junior union is run by Old Belvederians who have left the Belvedere in the last 10 years. They set their own agenda and run events with continue a strong social justice ethos, such as the Soup run and the Sleep Out, which support the homelessness. They also run activities to support their mental health and mentor students in Belvedere.

The Union has a strong historic connection to Old Belvedere Rugby Club, The Belvedere Benevolent Association and the Belvedere Youth Club. We are also connected with the past pupils unions from other Jesuit schools in Ireland through Jesuit Alumni Ireland.