| Simi Valley Unified, CA (District) |
| Simms H S, MT (District) |
| Simms ISD, TX (District) |
| Simpson Co School Dist, MS (District) |
| Simpson County, KY (Phantom) |
| Simpson County, MS (ISD) |
| Simpson County Schools, KY (District) |
| Simsbury School District, CT (District) |
| Sinclair Community Coll, OH (District) |
| Sinton ISD, TX (District) |
| Sioux Center Comm School District, IA (District) |
| Sioux Central Comm School District, IA (District) |
| Sioux City Comm School District, IA (District) |
| Sioux County, IA (ISD) |
| Sioux County, ND (ISD) |
