C
- (Mayo County) Cave
- (Mayo County) Carn
- (Mayo County) Carrowbaun
- (Mayo County) Cashels
- (Mayo County) Carrowneden
- (Mayo County) Coolnaha North
- (Mayo County) Coolnaha South
- (Mayo County) Cornageaghta
- (Mayo County) Cloonnagleragh
- (Mayo County) Cloondace
- (Mayo County) Cuillatinny
- (Mayo County) Cloontarriff
- (Mayo County) Cregganbrack
- (Mayo County) Carrownamallaght
- (Mayo County) Caher
- (Mayo County) Cloonnahulty
- (Mayo County) Canbrack
- (Mayo County) Cuilgar
- (Mayo County) Cuiltybo
- (Mayo County) Castleroyan
- (Mayo County) Carrownaculla
- (Mayo County) Castlecrunnogg
- (Mayo County) Castlesheenaghan
- (Mayo County) Castlebarnagh
- (Mayo County) Carn
- (Mayo County) Carrowbeg
- (Mayo County) Cuillaun
- (Mayo County) Carrowbaun
- (Mayo County) Carrowcanada
- (Mayo County) Carrowliam Beg