15 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Jurupa Valley | Riverside County | 109,553 |
| Jamul | San Diego County | 6,722 |
| Joshua Tree | San Bernardino County | 6,618 |
| Jackson | Amador County | 5,121 |
| Jamestown | Tuolumne County | 3,856 |
| Janesville | Lassen County | 2,687 |
| Jones Valley | Shasta County | 1,492 |
| Julian | San Diego County | 1,488 |
| Junction City | Trinity County | 1,177 |
| Johnson Park | Shasta County | 974 |
| Jacumba | San Diego County | 954 |
| Johnstonville | Lassen County | 954 |
| June Lake | Mono County | 112 |
| Johannesburg | Kern County | 55 |
| Jovista | Kern County | 17 |