| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Clair | city | California | United States | 33.81 | -117.98 | 52 | |
| Clairemont | city | California | United States | 32.80 | -117.19 | 180 | |
| Clam Beach | city | California | United States | 40.99 | -124.11 | 141 | |
| Claraville | city | California | United States | 35.44 | -118.33 | 6709 | |
| Clare Mill | city | California | United States | 39.42 | -123.43 | 1669 | |
| Claremont | city | California | United States | 34.10 | -117.72 | 1204 | |
| Claremont | city | California | United States | 37.86 | -122.25 | 318 | |
| Claribel | city | California | United States | 37.71 | -120.83 | 183 | |
| Clarksburg | city | California | United States | 38.42 | -121.53 | 3 | |
| Clarksville | city | California | United States | 38.65 | -121.05 | 830 | |
| Clarsona | city | California | United States | 38.37 | -120.98 | 334 | |
| Claus | city | California | United States | 37.69 | -120.92 | 101 | |
| Claussenius | city | California | United States | 38.85 | -120.61 | 4199 | |
| Clay | city | California | United States | 38.34 | -121.16 | 147 | |
| Clayton | city | California | United States | 37.94 | -121.94 | 403 | |
| Clayton | city | California | United States | 38.91 | -121.31 | 150 | |
| Clayton (historical) | city | California | United States | 34.03 | -118.03 | 314 | |
| Clear Creek | city | California | United States | 41.71 | -123.45 | 997 | |
| Clear Creek | city | California | United States | 40.30 | -121.05 | 5029 | |
| Clear Creek Mobile Home Park | city | California | United States | 40.51 | -122.38 | 830 | |
| Clear Lake Keys | city | California | United States | 39.02 | -122.66 | 1669 | |
| Clear Lake Riviera | city | California | United States | 38.95 | -122.72 | 1945 | |
| Clearing House | city | California | United States | 37.66 | -119.87 | 1669 | |
| Clearlake | city | California | United States | 38.96 | -122.63 | 1669 | |
| Clearlake Highlands | city | California | United States | 38.96 | -122.64 | 1669 | |
| Clearlake Oaks | city | California | United States | 39.03 | -122.67 | 1669 | |
| Clearlake Park | city | California | United States | 38.97 | -122.65 | 1669 | |
| Clearwater | city | California | United States | 33.90 | -118.16 | 82 | |
| Clement Junction | city | California | United States | 34.01 | -118.24 | 196 | |
| Clements | city | California | United States | 38.19 | -121.09 | 121 | |
| Clems (historical) | city | California | United States | 37.10 | -122.00 | 908 | |
| Cleone | city | California | United States | 39.49 | -123.79 | 157 | |
| Cliff Haven | city | California | United States | 33.63 | -117.92 | 9 | |
| Clifton | city | California | United States | 33.83 | -118.38 | 114 | |
| Cliftwood Mobile Home Park | city | California | United States | 36.99 | -121.94 | 127 | |
| Clima | city | California | United States | 38.25 | -122.07 | 26 | |
| Clint | city | California | United States | 36.43 | -119.77 | 196 | |
| Clinton | city | California | United States | 38.38 | -120.67 | 2014 | |
| Clinton (historical) | city | California | United States | 37.80 | -122.25 | 32 | |
| Clio | city | California | United States | 39.74 | -120.58 | 4396 | |
| Clipper Gap | city | California | United States | 38.97 | -121.02 | 1758 | |
| Clipper Mills | city | California | United States | 39.53 | -121.16 | 3490 | |
| Clotho | city | California | United States | 36.72 | -119.61 | 298 | |
| Clover Flat | city | California | United States | 32.66 | -116.41 | 3349 | |
| Cloverdale | city | California | United States | 40.47 | -122.48 | 830 | |
| Cloverdale | city | California | United States | 38.81 | -123.02 | 390 | |
| Cloverleaf Canyon | city | California | United States | 34.17 | -118.00 | 1669 | |
| Clovis | city | California | United States | 36.83 | -119.70 | 364 | |
| Clyde | city | California | United States | 32.92 | -114.97 | 387 | |
| Clyde | city | California | United States | 38.03 | -122.03 | 16 |