CFS
- CFS (file format)
- Call for service
- Canada Flight Supplement
- Canadian Federation of Students
- Canadian Forces Station
- Canadian Forest Service
- Causal fermion systems
- Center for Financial Studies
- Center for Subjectivity Research
- Central Flying School
- Central Flying School RAAF
- Central Flying School RNZAF
- Central Flying School SAAF
- Centre for Food Safety
- Certificat de formation à la sécurité
- Chicken-fried steak
- Child and family services
- Christian Family Solutions
- Chromosomal fragile site
- Chronic fatigue syndrome
- Citizens for Sunshine
- Citywide Ferry Service
- Climate Forecast System (NCEP)
- Clustered file system
- Co-operative Financial Services
- Coffs Harbour Airport
- Cold-formed steel
- Committee on World Food Security
- Commonwealth Fusion Systems
- Completely Fair Scheduler
- Congo Free State
- Conservative Future Scotland
- Consolidated financial statement
- Continuous flash suppression
- Continuous flow system
- Corpo Forestale dello Stato
- Craigmillar Festival Society
- Cubic feet per second
- Côte française des Somalis
- Empire Airlines
- Microsoft Combat Flight Simulator
- Myalgic encephalomyelitis/chronic fatigue syndrome
- Sartigan Railway
- South Australian Country Fire Service
- Syrian Railways