| Signal Hill SD 181, IL (District) |
| Signature School Inc, IN (District) |
| Sigourney Comm School District, IA (District) |
| Sikeston R-6, MO (District) |
| Silex R-I, MO (District) |
| Silo, OK (District) |
| Siloam Springs School District, AR (District) |
| Silsbee ISD, TX (District) |
| Silver Bow, MT (District) |
| Silver Bow County, MT (ISD) |
| Silver Consolidated Schools, NM (District) |
| Silver Creek Central School District, NY (District) |
| Silver Creek School Corporation, IN (District) |
| Silver Falls Sd 4J, OR (District) |
| Silver Fork Elementary, CA (District) |
