C
- (Mayo County) Cartronduff
- (Mayo County) Carrowclogher
- (Mayo County) Carrowjames
- (Mayo County) Cloghanlucas North
- (Mayo County) Cloonflyn
- (Mayo County) Cloonconragh
- (Mayo County) Cogaula
- (Mayo County) Clogherowan
- (Mayo County) Cloghboley
- (Mayo County) Creggannavar
- (Mayo County) Carrownaraha
- (Mayo County) Carrowntleva
- (Mayo County) Carrownteeaun
- (Mayo County) Camderrynabinnia
- (Mayo County) Carrowndangan
- (Mayo County) Carrigeen Lough
- (Mayo County) Cornamonaster
- (Mayo County) Corvickremon
- (Mayo County) Cornahavoley
- (Mayo County) Creevagh
- (County Galway) Coogla
- (County Galway) Crumpan
- (County Galway) Creig an Chéirín
- (County Galway) Corrúch
- (Mayo County) Collan More
- (Sligo) Charlestown-Bellahy
- (County Galway) Carna Village
- (Mayo County) Casheltourly
- (Mayo County) Cloghvoley
- (Mayo County) Cartron