- CAIS (Community Advice and Information Service)
- CAISE (Computer Aided Integrated Software Engineering)
- CAISO (California Independent System Operator Corporation, a Regional Transmission Organization. (US))
- CAIT (Committee for Applied Instructional Technologies)
- CAJ (Canaima Airport)
- CAK (Akron-Canton Regional Airport)
- CAL (Canadian Arsenals Limited)
- CALA (Community Airborne Library Architecture)
- CALABARZON (A region in the Philippines: CAvite, LAguna, BAtangas, Rizal, queZON)
- CALAS (Consortium For African And Latin American Studies)
- CALC (Caring About Limestone Community)
- CALCE (Center for Advanced Life Cycle Engineering)
- CALCM (Conventional Air-Launched Cruise Missile)
- CALD (Cultural And Linguistic Diversity)
- CALE (Computer Aided Language Engineering)
- CALFEX (Combined Arms Live Fire Exercise)
- CALI (calliper log)
- CALICO (Computer-Assisted Language Instruction COnsortium)
- CALICS (Communication, Authentication, Location, Intentions, Condition, and Situation)
