C
- (County Donegal) Casheltown
- (County Donegal) Cashelmore
- (County Donegal) Carrowmenagh
- (County Donegal) Carrowkeel
- (County Donegal) Carrowen
- (An Cabhán) Carrigan
- (County Donegal) Carrickmore Upper
- (County Donegal) Carrickmore Lower
- (County Donegal) Carnowen
- (County Donegal) Carnmalin
- (County Donegal) Carn
- (An Cabhán) Cargagh
- (An Cabhán) Canningstown
- (County Donegal) Cabry
- (County Donegal) Creehennan
- (County Donegal) Claggan
- (County Donegal) Claggan
- (County Donegal) Clogherny
- (County Donegal) Claggan
- (County Donegal) Culkeeny
- (County Donegal) Calf Island
- (County Donegal) Corveen
- (County Donegal) Crockaneeve
- (County Donegal) Cashelnagor
- (County Donegal) Cashel Hill
- (County Donegal) Carowcanon
- (County Donegal) Croaghlosky
- (County Donegal) Crockglass
- (County Donegal) Creevagh
- (County Donegal) Cashel