Identifiers: city · CDP
| Rank | Community | Population |
|---|---|---|
| 1 | Anaheim (city), CA | 346,824 |
| 2 | Santa Ana (city), CA | 310,227 |
| 3 | Irvine (city), CA | 307,670 |
| 4 | Fontana (city), CA | 208,393 |
| 5 | Ontario (city), CA | 175,265 |
| 6 | Rancho Cucamonga (city), CA | 174,453 |
| 7 | Garden Grove (city), CA | 171,949 |
| 8 | Corona (city), CA | 157,136 |
| 9 | Pomona (city), CA | 151,713 |
| 10 | Fullerton (city), CA | 143,617 |
| 11 | Orange (city), CA | 139,911 |
| 12 | Pasadena (city), CA | 138,699 |
| 13 | East Los Angeles (CDP), CA | 118,786 |
| 14 | Downey (city), CA | 114,355 |
| 15 | West Covina (city), CA | 109,501 |
| 16 | El Monte (city), CA | 109,450 |
| 17 | Jurupa Valley (city), CA | 105,053 |
| 18 | Norwalk (city), CA | 102,773 |
| 19 | Chino (city), CA | 91,403 |
| 20 | Westminster (city), CA | 90,911 |