9 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Urbandale | Polk County | 48,850 |
| Urbana | Benton County | 1,671 |
| University Heights | Johnson County | 1,170 |
| Underwood | Pottawattamie County | 982 |
| University Park | Mahaska County | 470 |
| Union | Hardin County | 371 |
| Ute | Monona County | 318 |
| Unionville | Appanoose County | 73 |
| Udell | Appanoose County | 30 |