C
- (Province of Isabela) Calao
- (Province of Isabela) Calanigan
- (Province of Isabela) Calamagui Second
- (Province of Isabela) Calamagui First
- (Province of Cagayan) Calamagui
- (Province of Isabela) Caladinum
- (Province of Isabela) Calaccab
- (Province of Isabela) Calabayan-Minanga
- (Province of Isabela) Calabayan
- (Province of Isabela) Calabasa
- (Province of Cagayan) Cagumitan
- (Province of Cagayan) Cagoran
- (Province of Isabela) Cago
- (Province of Isabela) Caggong
- (Province of Isabela) Caggong
- (Province of Cagayan) Caggay
- (Province of Cagayan) Caggay
- (Province of Quirino) Cagadiagan
- (Province of Isabela) Cadu
- (Province of Cagayan) Cadongdongan
- (Province of Isabela) Caddangan
- (Province of Cagayan) Cadcadir
- (Province of Quirino) Cada Negrito
- (Province of Cagayan) Cadagatan
- (Province of Cagayan) Cadadalman
- (Province of Isabela) Cadaanan
- (Province of Isabela) Caculucuan
- (Province of Cagayan) Caccag
- (Province of Cagayan) Caucauayan
- (Province of Cagayan) Cacaluan