| Abbreviation | Definition |
|---|---|
| CTRA | Cooperative Teamwork and Recycling Assistance |
| CTRA | Cowichan Therapeutic Riding Association |
| CTRC | Colorado Therapeutic Riding Center |
| CTRE | Canadian Textile Recovery Effort |
| CTRF | Commonwealth Technology Research Fund |
| CTRF | Gateway for Cancer Research (previously Cancer Treatment Research Foundation) |
| CTRFSP | Commonwealth Technology Research Fund Sponsored Project |
| CTRH | Cincinnati Therapeutic Riding and Horsemanship |
| CTRI | Community Training and Resource Institute |
| CTRN | Central Texas Respite Network |
| CTRP | Center for Trauma Response, Recovery, and Preparedness |
| CTR-USA | Council for Tobacco Research - United States of America |
| CTS | Center for Traffic Statistics |
| CU | Consumers Union |
| CU | Consumers' Union |
| CUFA | Citizens United For Animals |
| CUFL | Catholics United For Life |
| CUL | Catholics United for Life |
| CURE | Caucasians United for Reparations and Emancipation |
| CURE | Citizens United Resisting Euthanasia |