- Casmael
- Casnewydd
- Castle Caereinion
- Castle Community
- Castlemartin
- Castlemorris
- Castleton
- Caswell
- Catbrook
- Cathedine
- Cefn
- Cefn-bryn-brain
- Cefn-bychan
- Cefn-coed-y-cymmer
- Cefn Cribwr
- Cefn Mawr
- Cefn-y-bedd
- Cefn-y-pant
- Cefneithin
- Cei Connah
- Ceinws
- Cellan
- Cemaes Bay
- Cemmaes
- Cemmaes Road
- Cenarth
- Cerrig-y-Druidion
- Cerrigydrudion
- Ceunant
- Chepstow