The initialism "CAP", when used by itself, can refer to:
- California Assessment Program, a California standards test replaced by the California Learning Assessment System, which was in turn replaced by the STAR system.
- Camel Application Part, a protocol used in CAMEL servers.
- Canadian Action Party
- Canadian Association of Physicists
- Carlos Andrés Pérez, was a president of Venezuela.
- Carrierless Amplitude Phase Modulation
- Catabolite Activator Protein
- Center for American Progress, a left-of-center think tank.
- Central Arizona Project Aqueduct
- Central Atlanta Progress
- Certified Administrative Professional
- Chicago Area Project
- ChildCare Action Project
- Christian Appalachian Project a faith-based program to assist disadvantaged persons in the Appalachian region of Kentucky.
- Civil Air Patrol
- Coded Anti-Piracy, an anti-piracy system for motion picture prints exhibited theatrically.
- College of American Pathologists
- Combat Air Patrol
- Communication Arts Program
- Common Agricultural Policy, the European Union's agricultural subsidy system.
- Common Alerting Protocol
- Community-acquired pneumonia
- Concerned Alumni of Princeton
- Critical Analysis of Popculture