C
- Cabragh River, County Sligo
- Callan*
- River Camac, County Dublin
- Camlough*
- Camowen*
- Carey*
- Carn River, County Mayo
- Carrickbrack Stream, County Dublin
- Carrickmines River, County Dublin
- Carrowbeg
- Carryduff*
- Carysfort-Maretimo Stream, County Dublin
- Castle Stream, County Dublin
- Castletown River, County Louth
- Cemetery Drain, County Dublin
- Cladagh*
- Clady*
- Clanrye*
- Clare
- Claremont Stream, County Dublin
- Cloonaghmore River, County Mayo
- Colebrooke*
- Commons Water, County Dublin
- Coolcour Brook, County Dublin
- Corduff River, County Dublin
- Corrib
- Cot Brook, County Dublin
- County Brook, County Dublin
- Cregg
- Creosote Stream, County Dublin
- Crinken Stream, County Dublin
- Crompaun River, County Clare
- Crumlin*
- Cuckoo Stream, County Dublin
- Cumber*
- Cusher*
Read more about this topic: Rivers Of Northern Ireland