| Underwood 8, ND (District) |
| Underwood Comm School District, IA (District) |
| Underwood Public School District, MN (District) |
| Unicoi County, TN (District) |
| Unicoi County, TN (ISD) |
| Unified School District #1, CT (District) |
| Unified School District #2, CT (District) |
| Unified School District #3, CT (District) |
| Union, OK (District) |
| Union, FL (District) |
| Union 01, SC (District) |
| Union Academy, NC (District) |
| Union Area SD, PA (District) |
| Union Beach Public School District, NJ (District) |
| Union City, TN (District) |
