S
- Sacred Heart Grammar School, Newry, County Down
- St Colman's College, Newry, County Down
- St Columb's College, Derry
- St. Dominic's High School, Belfast
- St Joseph's Grammar School, Donaghmore, County Tyrone
- St Louis Grammar School, Ballymena, Ballymena, County Antrim
- St Louis Grammar School, Kilkeel, Kilkeel, County Down
- Strabane Grammar School, Strabane, County Tyrone
- St. Malachy's College, Belfast
- St Mary's Christian Brothers Grammar School, Belfast
- St Mary's Grammar School, Magherafelt, County Londonderry
- St Michael's College, Enniskillen, County Fermanagh
- St Michael's Grammar School, Lurgan, Lurgan, County Armagh
- St Patrick's Academy, Dungannon, County Tyrone
- St Patrick's Grammar School, Armagh
- St. Patrick's Grammar School, Downpatrick, Downpatrick, County Down
- Strathearn School, Belfast
- Sullivan Upper School, Holywood, County Down
Read more about this topic: List Of Grammar Schools In Northern Ireland