| Name | School | Sub-Type |
|---|---|---|
| CHINESE INSTIUTE OF ENGINEERS | ||
| CHINESE SCHOOL | Classification 3 | |
| CLASS OF 1959 | ||
| CRY America | Classification 3 | |
| California Institute of Technology | Classification 3 | |
| Carnegie Mellon University | ||
| Carriage Hills Condo Assoc. | Classification 3 | |
| Cascade Dance Academy | Classification 4 | |
| Cascade and Olympic Programs | Newport High School | |
| Cedar Crest Academy | Classification 3 | |
| Champion Youth Outreach | ||
| Cheetah Flips DBA Swerve Driving School | ||
| Chevy Club | Classification 1 | |
| Chevy's Speed and Agility | ||
| Child Rights and You (CRY Seattle) | ||
| Chinook Community | ||
| Chinook I-Team | Chinook Middle School | |
| Chinook Middle School Badminton | Chinook Middle School | |
| Chinook/Friends of Hoop | Classification 2 | |
| City of Bellevue | Classification 2 | |
| City of Bellevue Basketball | ||
| City of Bellevue Residence | ||
| City on a Hill | Classification 2 | |
| ClearPoint Financial | ||
| Club Volleyball | ||
| Clyde Hill Community User | ||
| Coal Creek Chapel | Classification 3 | |
| Color Guard | Newport High School | |
| Comeback Sports | ||
| Community User | Classification 2 |
