The Halifax Grammar School (HGS) is an independent, coeducational day school in Halifax, Nova Scotia, Canada. It is located in south-end Halifax, near Saint Mary's University. Approximately 500 students attend the school. At the high school level students take the International Baccalaureate (IB) Diploma Program. The school's current headmaster is Blayne Addley. All prospective students undergo limited entrance testing before being admitted.