C
- (Mayo County) Curraunboy
- (Mayo County) Carrowteige
- (Mayo County) Cregganbeg
- (Mayo County) Cloonvoragh
- (Mayo County) Corvoley
- (Mayo County) Cloonaghmore
- (Mayo County) Cloonachoor
- (Mayo County) Crevagh
- (Mayo County) Corhoor
- (Mayo County) Carrowcor
- (Mayo County) Corcoranstown
- (Mayo County) Conaghra
- (Mayo County) Carrowcuilleen
- (Mayo County) Cill Alaithe
- (Mayo County) Cloonfadda
- (County Galway) Cashel
- (Mayo County) Carnacon
- (Mayo County) Cushlough
- (Sligo) Coolrawer
- (Mayo County) Carrickdull
- (Mayo County) Carricknaweelion
- (Mayo County) Carrickaporl
- (Mayo County) Carrigee
- (Mayo County) Carricklaur
- (Mayo County) Carrigeenaballa
- (Mayo County) Carrickfad
- (Mayo County) Cone Island
- (Mayo County) Cone Island South
- (Mayo County) Cregganroe
- (Mayo County) Carn