15 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Jurupa Valley | Riverside County | 108,853 |
| Jamul | San Diego County | 6,687 |
| Joshua Tree | San Bernardino County | 6,667 |
| Jackson | Amador County | 5,100 |
| Jamestown | Tuolumne County | 3,830 |
| Janesville | Lassen County | 2,607 |
| Julian | San Diego County | 1,489 |
| Jones Valley | Shasta County | 1,398 |
| Junction City | Trinity County | 1,146 |
| Johnstonville | Lassen County | 958 |
| Jacumba | San Diego County | 929 |
| Johnson Park | Shasta County | 913 |
| June Lake | Mono County | 144 |
| Johannesburg | Kern County | 62 |
| Jovista | Kern County | 16 |