CTR
- CTRS
- Cardiac resynchronization therapy
- Cardio-thoracic ratio
- Carlton Trail Railway
- Carpal tunnel release
- Center (disambiguation)
- Center for Transportation Research UT Austin
- Center for Turbulence Research
- Cervico-thoracic ratio
- Chester railway station
- Choose the right
- Click-through rate
- Clinical trials registry
- Competitive trail riding
- Computing-Tabulating-Recording Company
- Contemporary Theatre Review
- Content Threat Removal
- Control (disambiguation)
- Controlled traffic region
- Cooperative Threat Reduction
- Correct the Record
- Costa Rica
- Counter mode
- Crash Team Racing
- Crash Team Racing Nitro-Fueled
- Currency transaction report
- Honda Civic Type R
- List of airline codes (A)
- Ruf CTR
- X-ray crystal truncation rod