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- Olderfleet Primary School, Larne, County Antrim
- Orangefield Primary School, Belfast, County Antrim
- Orritor Primary School, Cookstown, County Tyrone
- Our Lady's Primary School, Tullysaran, County Armagh
- Our Lady of Lourdes (Parklodge) Primary School, Belfast, County Antrim
- Our Lady Queen Of Peace Primary School, Dunmurry, Belfast, County Antrim
Read more about this topic: List Of Primary Schools In Northern Ireland