6 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| University Place | Pierce County | 35,224 |
| Union Hill-Novelty Hill | King County | 23,959 |
| Union Gap | Kittitas County | 6,589 |
| Uniontown | Whitman County | 397 |
| Union | Mason County | 227 |
| Upper Elochoman | Wahkiakum County | 79 |