C
- (Mayo County) Cummer
- (Mayo County) Cashel
- (Mayo County) Cloonfane
- (Mayo County) Cloonnamna
- (Mayo County) Cloonturk
- (Mayo County) Cloontarriff
- (Mayo County) Corhawnagh
- (Mayo County) Cloontubbrid
- (Mayo County) Curryaun
- (Mayo County) Cornaveagh
- (Mayo County) Cornageeha
- (Mayo County) Cloonainra
- (Mayo County) Cartron
- (Mayo County) Coogue North
- (Mayo County) Coogue South
- (Mayo County) Coogue Middle
- (Mayo County) Cloonfallagh
- (Mayo County) Corgarriff
- (Mayo County) Culliagh
- (Mayo County) Carrownlacka
- (Mayo County) Cloonierin
- (Mayo County) Cappulcorragh
- (Mayo County) Cashelduff
- (Mayo County) Carrowntober
- (Mayo County) Cornagallagh
- (Mayo County) Cloontaconnagh
- (Mayo County) Cloonfeightrin
- (Mayo County) Cloonakillina
- (Mayo County) Cloonmeen East
- (Mayo County) Cranmore