| Columbus Preparatory Academy, OH (PSA) |
| Columbus Preparatory and Fitness Academy, OH (PSA) |
| Columbus Public Schools, NE (District) |
| Columbus School District, WI (District) |
| Colusa County Office of Education, CA (District) |
| Colusa ESA, CA (ISD) |
| Colusa Unified, CA (District) |
| Colville School District, WA (District) |
| Comal County, TX (ISD) |
| Comal ISD, TX (District) |
| Comanche, OK (District) |
| Comanche County, OK (ISD) |
| Comanche County, TX (ISD) |
| Comanche County, KS (ISD) |
| Comanche County, KS (District) |
