C
- (Mayo County) Carrowkeel
- (Mayo County) Capparanny
- (Mayo County) Cashel
- (Mayo County) Corraun
- (Mayo County) Creggagh
- (Mayo County) Coolcronaun
- (Mayo County) Cuillonaghtan
- (Mayo County) Carrick
- (Mayo County) Coollagagh
- (Mayo County) Coolloughra
- (Mayo County) Clooncrooeel
- (Mayo County) Cooley
- (Mayo County) Cloonaghmore
- (Mayo County) Clooncanavan
- (Mayo County) Claggarnagh
- (Mayo County) Carrowmore
- (Mayo County) Curry
- (Mayo County) Curraghmore
- (Mayo County) Cloghannageeragh
- (Mayo County) Cushalogurt
- (Mayo County) Carrigeenglass North
- (Mayo County) Carrigeenglass
- (Mayo County) Carrigeenglass South
- (Mayo County) Carrownahaun
- (Mayo County) Carrowmore
- (Mayo County) Carrowkeel
- (Mayo County) Cartron
- (Mayo County) Carrowtober
- (Mayo County) Cuillare
- (Mayo County) Creaghanboy