Identifiers: city · CDP
| Rank | Community | Population |
|---|---|---|
| 1 | Vallejo (city), CA | 126,090 |
| 2 | Fairfield (city), CA | 119,881 |
| 3 | Richmond (city), CA | 116,448 |
| 4 | Vacaville (city), CA | 102,386 |
| 5 | Napa (city), CA | 79,246 |
| 6 | Novato (city), CA | 53,225 |
| 7 | Martinez (city), CA | 37,287 |
| 8 | Pleasant Hill (city), CA | 34,613 |
| 9 | San Pablo (city), CA | 32,127 |
| 10 | Suisun City (city), CA | 29,518 |
| 11 | Benicia (city), CA | 27,131 |
| 12 | El Cerrito (city), CA | 25,962 |
| 13 | American Canyon (city), CA | 21,837 |
| 14 | Pinole (city), CA | 19,022 |
| 15 | El Sobrante (CDP), CA | 15,524 |
| 16 | Sonoma (city), CA | 10,739 |
| 17 | Rodeo (CDP), CA | 9,653 |
| 18 | Contra Costa Centre (CDP), CA | 6,808 |
| 19 | Boyes Hot Springs (CDP), CA | 6,215 |
| 20 | Tara Hills (CDP), CA | 5,364 |