| Abbreviation | Definition |
|---|---|
| CISD | Carroll Independent School District |
| CISD | Conroe Independent School District |
| CISD | Coppell Independent School District |
| CISD | Crowley Independent School District |
| CISL | Converse International School of Languages |
| CISLA | Communities in Schools of Los Angeles |
| CISM | Chinese International School Manila |
| CISS | Canadian International School System |
| CISS | Concordia International School Shanghai |
| CISSA | Communities In Schools San Antonio |
| CISSN | Catania International Summer School of Neuroscience |
| CITS | College In the Schools |
| CITS | Computers In The Schools |
| CIVA | Character Integrity Vision and the Arts (Charter School, Colorado Springs, CO) |
| CJ | Chaminade Julienne High School |
| CJBS | Cambridge Judge Business School |
| CJDS | Center for Jewish Day Schools |
| CJDS | Charlotte Jewish Day School |
| CJDS | Chicago Jewish Day School |
| CJDS | Columbus Jewish Day School |