The school has a wide and varied programme of extra-curricular and cultural activities. There are regular educational and vocational visits both locally, in Ireland and to Europe.

The St. Mary's Choir, Folk Group and Traditional Music Makers perform in public with great distinction. The choir regularly takes part in Young Voices in the Odyssey Arena as well as singing in hospitals and nursing homes at Christmas and at school Masses. Music tuition is available in the school for violin, guitar and bodhran, flutes, piano and other stringed instruments.

Sports are central to the life of the school. Year after year our camogie and Gaelic football players at U-14 and U-16 and U-19 level reach the County finals. Basketball and netball are played with great success. A new development is Ladies' football. Hurling is growing in popularity, especially since we became Ulster Champions. There is a bi annual ski trip to Switzerland and an annual soccer trip to a premiership match.

Revision groups and study groups after school are set up & the need or interest arises. Lower 6th students avail of Driving Lessons and many take part in GAA Coaching schemes. Some of our pupils further develop their social awareness by visiting Lourdes at Easter. Lower 6th student can travel annually to work in Romanian Orphanages in the summer.

Fundraising and Charities

Throughout the year pupils organise fund raising events for various charities and appeals. This has included the Global Gift from Concern at Christmas, the Croatian Shoe Box Appeal, hampers for the local St.Vincent de Paul societies, fund raising for Children in Crossfire, Children in Need, Trocaire, the Northern Ireland Hospice, Action Cancer and support for Fr. Diamond and the SMA Fathers.

Education for Mutual Understanding

As a school community St. Mary's is strongly committed to developing good and fruitful working relationships with other communities and traditions. We particularly value our long-standing link with Cullybackey High School. This link is developed through social and curriculum-based educational visits.

EMU activities have included visits to Barcelona, Carrickfergus Castle, the Tower Museum and Guildhall, Derry as well as a residential in Co. Mayo. A new EMU development is Friends for Romania. Sixth Form students from St. Mary's travel to Eastern Europe along with Sixth Formers from Cambridge House Ballymena and St. Louis’ Ballymena and bring aid to the orphanages.