6 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| University Place | Pierce County | 35,147 |
| Union Hill-Novelty Hill | King County | 24,265 |
| Union Gap | Kittitas County | 6,365 |
| Uniontown | Whitman County | 388 |
| Union | Mason County | 350 |
| Upper Elochoman | Wahkiakum County | 85 |