| 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) |
| Sisu Environmental School, MN (PSA) |
| Sisulu-walker Charter School Of Harlem, NY (PSA) |
| Sisulu-Walker Cs, NY (PSA) |
| Sitka Borough, AK (ISD) |
