CAC
- Air carbon arc cutting
- CAC 40
- CPSU Central Auditing Commission
- Cairo American College
- Calcium carbide
- California Arts Council
- Call Admission Control
- Call Aircraft Company
- Campaign Against Censorship
- Campbelltown Arts Centre
- Canadian Aviation Corps
- Capital account convertibility
- Cardiff Athletic Club
- Carmel Adventist College
- Carrier access code
- Castles and Crusades
- Cauliflower Alley Club
- Central Advisory Commission
- Central Advisory Council
- Central American and Caribbean Games
- Central Arbitration Committee
- Central Arizona College
- Central Arkansas Christian Schools
- Central Asian Commonwealth
- Certified Acceptance Corporation
- Cessna
- Champion Aircraft Corporation
- Charge air cooler
- Chengdu Aircraft Corporation
- Christ Apostolic Church
- Christians Against the Coup
- Chugach Alaska Corporation
- Church at Charlotte
- Citric acid cycle
- Ciutat de les Arts i les Ciències
- Coast to Coast Athletic Conference
- Codex Alimentarius Commission
- Collective action clause
- Colombian armed conflict (1964–present)
- Colonial Ammunition Company
- Combined Action Company
- Comics Arts Conference
- Commissioner's Academic Challenge
- Common Access Card
- Commonwealth Aircraft Corporation
- Commonwealth Athletic Conference
- Confédération Africaine de Cyclisme
- Congressional App Challenge
- Conquest Airlines
- Consolidated Aircraft Corporation
- Constitutional Accountability Center
- Contemporary Arts Center
- Coomera Anglican College
- Copa Airlines Colombia
- Copa América Centenario
- Coronary CT calcium scan
- Corporate Affairs Commission, Nigeria
- Cotation Assistée en Continu
- Cricket Australia Cup
- Criteria air contaminants
- Customer acquisition cost
- Cyberspace Administration of China
- Montreal Canadiens
- Royal Canadian Armoured Corps
- U.S. Army Coast Artillery Corps
- United States Army Combined Arms Command