| Sioux Central Comm School District, IA (District) |
| Sioux City Comm School District, IA (District) |
| Sioux County, IA (ISD) |
| Sioux County, ND (ISD) |
| Sioux County, NE (ISD) |
| Sioux County Public Schools, NE (District) |
| Sioux Falls School District, SD (District) |
| Sioux Valley School District, SD (District) |
| Siren School District, WI (District) |
| Siskiyou County Office of Education, CA (District) |
| Siskiyou ESA, CA (ISD) |
| Siskiyou ROP, CA (District) |
| Siskiyou Union High, CA (District) |
| Sisseton School District, SD (District) |
| Sisters Sd 6, OR (District) |
