- Cloverleaf Canyon
- Country Mobile Estates
- Cypave
- Copperopolis
- Corcoran
- Corning
- Corona
- Coronado
- Corralitos
- Corte Madera
- Costa Mesa
- Costa Mesa Mobile Home Estates
- Cotati
- Coto De Caza
- Country Club
- Covina
- Cascadel Woods
- Central Camp
- Chapman
- Childrens Island
- Cypress Grove
- Crescent City
- Crescent Mills
- Crest
- Crestline
- Crockett
- Cromberg
- Cudahy
- Clearing House
- Curry Village