At Kilgraston the religious and spiritual development of its students is paramount, whatever their creed or religion and the Society of the Sacred Heart's goals continue to provide the basis for education and life at Kilgraston.

As a Catholic school with a strong ecumenical tradition, preparation for confirmation is available not just for the Catholics but also for those from other Christian denominations.

The School Chaplain, Fr Andrew Clark, is usually available to all pupils and staff three days a week. Mass is celebrated in school every Sunday and there is also an optional Mass on Thursdays. Whilst all non Catholics are very welcome to join in the celebrations of Mass there is no obligatory requirement.