About
St Mary’s CBGS Belfast is an all-boys voluntary grammar school in West Belfast with a proud tradition dating back to 1866.
Founded by the Christian Brothers and now based on the Glen Road, the school is known for its strong pastoral care, academic excellence, and commitment to the holistic development of every pupil. Guided by the values of trust, respect and equality, St Mary’s provides a supportive environment where students are encouraged to achieve their potential, build lasting friendships, and grow into confident, motivated young men
History
St Mary’s belongs to the international group of schools served by the Congregation of Irish Christian Brothers.
St Mary’s is an Edmund Rice Schools Trust (ERST) School. It is inspired by the vision of Edmund Rice to create school communities dedicated to the pursuit of excellence in teaching and learning, and which cultivate Gospel-based values. The School was founded in 1866 to provide education for day pupils in the Belfast area.
Most Rev. Dr. Dorrian, Bishop of Down and Connor, invited the Irish Christian Brothers to Belfast in 1866. Four Brothers arrived in Belfast on 3rd November and took up residence at 26 Regent Street. On 12th November 1866, St. Mary’s opened its doors and over three hundred students enrolled on the first day.
In 1868, the Bishop asked the Brothers to open a second school, St. Patrick’s, Donegall Street. Further expansion took place with the opening of the Oxford Street School in 1874. From the beginning, all three schools provided primary and secondary education
However in 1924, it was decided to build a completely separate secondary school, and a site was purchased in Barrack Street. St. Mary’s was opened in 1929. With the population explosion of the 1960s, this site proved totally inadequate and it was decided to build a new Grammar School on the Glen Road, where we have remained since 1968. We now cater for over 1,200 pupils. To facilitate junior students, from north, south and east Belfast, junior classes were still held in St. Mary’s Barrack Street until 1998. From September 1999, all lessons moved to our site on Glen Road. As a Christian Brothers’ School, Catholic religious and moral education is central to the School’s Educational and Religious Philosophy.
School Ethos and Core Values
The ethos of St Mary’s CBGS is captured best in our Vision Statement: In the tradition of Edmund Rice, we promote our faith, champion our social justice, nurture a culture of inclusivity, that prioritise the values and virtues of trust, respect and equality, celebrate success, elevate expectations, engage with local community and foster a climate that improves the health and wellbeing of all Simmarians Our core values, decided by our pupils and staff , are:

