| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Rubicon Properties | city | California | United States | 39.01 | -120.12 | 6227 | |
| Rubicon Springs (historical) | city | California | United States | 39.02 | -120.25 | 6197 | |
| Rubidoux | city | California | United States | 34.00 | -117.41 | 830 | |
| Rucker | city | California | United States | 37.05 | -121.59 | 226 | |
| Rugg (historical) | city | California | United States | 36.73 | -120.01 | 236 | |
| Rumsey | city | California | United States | 38.89 | -122.24 | 830 | |
| Running Springs | city | California | United States | 34.21 | -117.11 | 6092 | |
| Runnymeade (historical) | city | California | United States | 37.47 | -122.13 | 29 | |
| Runnymede Poultry Colony (historical) | city | California | United States | 34.21 | -118.52 | 830 | |
| Ruscisilva | city | California | United States | 34.10 | -118.33 | 360 | |
| Russ | city | California | United States | 34.44 | -118.31 | 2509 | |
| Russ Place | city | California | United States | 40.15 | -123.28 | 4189 | |
| Russell | city | California | United States | 38.24 | -122.10 | 32 | |
| Russell City | city | California | United States | 37.65 | -122.13 | 49 | |
| Russian River Terrace | city | California | United States | 38.50 | -122.93 | 396 | |
| Ruth | city | California | United States | 40.27 | -123.32 | 2798 | |
| Rutherford | city | California | United States | 38.46 | -122.42 | 170 | |
| Ruthven | city | California | United States | 32.95 | -115.01 | 374 |