| Acronym | Definition |
|---|
| OCA | Orthodox Church in America |
| OCA | Organic Consumers Association |
| OCA | Office of Consumer Affairs |
| OCA | Organization of Chinese Americans |
| OCA | Office of Consumer Advocate (Pennsylvania) |
| OCA | Oculocutaneous Albinism (inherited disorder) |
| OCA | Office of the Court Administrator |
| OCA | Ontario Cattlemen’s Association |
| OCA | Oregon Citizens Alliance (political group) |
| OCA | oculocutaneous albinism |
| OCA | Offensive Counter Air |
| OCA | Obstacle Clearance Altitude |
| OCA | Orthodontic Centers of America |
| OCA | Ontario Chiropractic Association (Association Chiropratique de l'Ontario) |
| OCA | Obsessive Compulsive Anonymous |
| OCA | Office of Congressional Affairs |
| OCA | Oceanic Control Area |
| OCA | Orlando Culinary Academy |
| OCA | Office of Community Affairs (law enforcement) |
| OCA | One Cancels All (online stock trading) |
| OCA | Outdoor Council of Australia (Queensland, Australia) |
| OCA | Originating Case Agency |
| OCA | Office of Chief Architect (GSA) |
| OCA | Owner Controlled Area |
| OCA | Ohio Chess Association |
| OCA | Officials Club Automobielsport (Dutch Club of Flag and Rescuemarshals for Automobile-Sports) |
| OCA | Ohio Connections Academy (subdivision of US K-8 online school) |
| OCA | Oxford Conservative Association (formerly Oxford University Conservative Association; UK) |
| OCA | Overlapping Claim Area |
| OCA | Objectivist Club Association |
| OCA | Orbiter Communication Adapter |
| OCA | Operating Cost Authority |
| OCA | Overflow Channel Allocation |
| OCA | Operational Capability Area (GIG IA architecture version 1.1) |
| OCA | Older Coloradans Act |
| OCA | Overall Configuration Analyses |
| OCA | One's Complement Adder |
| OCA | Office Connect Analytics (IBM) |
| OCA | Operational Concept Approved |
| OCA | Organizational Culture Obstacle |
| OCA | Original Classification/Classifying Authority |
| OCA | Original Controlling Authority |
| OCA | Optimized Cage Antenna |
| OCA | Omni-Directional/Channel Assignment |
| OCA | Obligation Cost Authority |
| OCA | Offsite Consequence Analysis |
| OCA | On Call Allowance |
| OCA | Office of Court Administration |
| OCA | Operational Control Authority |
| OCA | Optical Channel Analyzer |
| OCA | Ontario College of Art |
| OCA | Ontario Comprehension Assessment (Canada) |
| OCA | Ontario Citizens' Assembly |
| OCA | Organized Crime Agency of British Columbia (Canada) |
| OCA | Oldsmobile Club of America |
| OCA | Olympic Council of Asia |
| OCA | Ohio Citizen Action |
| OCA | Ontario Court of Appeal (Canada) |
| OCA | Open Content Alliance |
| OCA | Office of Cultural Affairs (New Mexico, USA) |
| OCA | Online Crash Analysis (Microsoft Windows) |
| OCA | Off-Campus Access (various schools) |
| OCA | Optimum Currency Area |
| OCA | Office of the City Attorney (various locations) |
| OCA | Olympic Coordination Authority (Australia) |
| OCA | Office of Campus Activities (various schools) |
| OCA | Ontario Camping Association (Toronto, ON, Canada) |
| OCA | Oracle Certified Associate |
| OCA | Oberlin College Archives (Oberlin, OH) |
| OCA | Off Course Alarm (navigation equipment) |
| OCA | Operational Command Authority |