| Cincinnati City School District, OH (District) |
| Cincinnati Classical Academy, OH (PSA) |
| Cincinnati College Preparatory Academy, OH (PSA) |
| Cincinnati Technology Academy, OH (PSA) |
| Cincinnatus Central School District, NY (District) |
| Cinnabar Elementary, CA (District) |
| CINNAMINSON TOWNSHIP PUBLIC SCHOOLS, NJ (District) |
| Circle, KS (District) |
| Circle City Prep Charter School, IN (District) |
| Circle Elem, MT (District) |
| Circle H S, MT (District) |
| Circle of Seasons CS, PA (PSA) |
| Circleville City School District, OH (District) |
| Cirrus Charter Academy, GA (PSA) |
| Cis Academy, NC (District) |
