- Carnegie Hill
- Caroga Lake
- Caroline
- Caroline
- Caroline Center
- Caroline Depot
- Carpenters Acres
- Carpenters Corners
- Carriage Estates
- Carroll
- Carrollton
- Carter's Mobile Home Park
- Carterville
- Cartwright Island
- Cascade
- Cascade Acres Mobile Home Park
- Cascade Valley
- Casino Island
- Casowasco
- Cassville
- Castle Creek
- Castle Francis Island
- Castle Gate Mobile Home Park
- Castle High Estates
- Castle Hill Houses
- Castle Point
- Castleton Corners
- Castlewood
- Casual Estates
- Cat Elbow Corner