| Castle Rock School District, WA (District) |
| Castle Rock Union Elementary, CA (District) |
| Castleberry ISD, TX (District) |
| Castleford District, ID (District) |
| Castlewood School District, SD (District) |
| Caston School Corporation, IN (District) |
| Castro County, TX (ISD) |
| Castro Valley Unified, CA (District) |
| Caswell County, NC (ISD) |
| Caswell County Schools, NC (District) |
| Caswell School Department, ME (District) |
| Catahoula Parish, LA (ISD) |
| Catahoula Parish, LA (District) |
| Catalina Foothills Unified District, AZ (District) |
| Catalyst Academy CS, PA (PSA) |
