Coleraine Grammar School is a co-educational voluntary grammar school in Coleraine, County Londonderry. It was created in 2015 through the merger of Coleraine Academical Institution and Coleraine High School. For its first decade the school operated across two sites on Castlerock Road and Lodge Road. In November 2024 all year groups moved into the fully redeveloped Castlerock Road campus.
The campus covers more than fifty acres and includes rugby pitches, extensive playing fields, a river boathouse on the Bann and a new hockey pitch scheduled for completion in 2025. The school enrols just over one thousand pupils aged eleven to eighteen and employs more than seventy teachers. It is a member of the Headmasters' and Headmistresses' Conference, reflecting its academic grammar school status.
David Carruthers serves as headmaster.