CTF
- Cambridge Theological Federation
- Canadian Taxpayers Federation
- Canadian Teachers' Federation
- Canadian Television Fund
- Capture the flag
- Capture the flag (cybersecurity)
- Catford railway station
- Charge trap flash
- Child Trust Fund
- Children's Tumor Foundation
- Chlorine trifluoride
- Chow Tai Fook
- Clean Technology Fund
- Coatepeque Airport
- Colorado tick fever
- Computer to film
- Contrast threshold function
- Contrast transfer function
- Controlled Traffic Farming
- Controlled thermonuclear fusion
- Correctional Training Facility
- Counter terrorism financing
- Cut-through forwarding
- Cyprus Tennis Federation
- Task force
- Text Services Framework