- Caheny
- Callaghanstown
- Callan Bridge
- Camlough
- Cape Castle
- Cargan
- Carland
- Carmavy
- Carn
- Carnagh
- Carncastle
- Carneatly
- Carnlough
- Carnmoney
- Carnteel
- Carr
- Carrickfergus
- Carrickmore
- Carrowdore
- Carryduff
- Castlecaulfield
- Castledawson
- Castlederg
- Castlereagh
- Castlerock
- Castlewellan
- Causeway Head
- Churchtown
- Clabby
- Clady
