***** 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 Ohio Connections Academy (subdivision of US K-8 online school)
** OCA Oxford Conservative Association
** 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 One's Complement Adder
* OCA Office Connect Analytics (IBM)
* OCA Operational Concept Approved
* OCA Overall Configuration Analyses
* OCA Original Classification/Classifying Authority
* OCA Original Controlling Authority
* OCA Optimized Cage Antenna
* OCA Organizational Culture Obstacle
* OCA Omni-Directional/Channel Assignment
* OCA Obligation Cost Authority
* OCA Oberlin College Archives (Ohio)
* OCA Off Course Alarm (navigation equipment)
* OCA Off-Campus Access (various schools)
* OCA Office of Campus Activities (various schools)
* OCA Office of Court Administration
* OCA Office of Cultural Affairs (New Mexico, USA)
* OCA Office of the City Attorney (various locations)
* OCA On Call Allowance
* OCA Ohio Citizen Action
* OCA Online Crash Analysis (Microsoft Windows)
* OCA Ontario Camping Association (Toronto, ON, Canada)
* OCA Oldsmobile Club of America
* OCA Olympic Coordination Authority (Australia)
* OCA Olympic Council of Asia
* OCA Offsite Consequence Analysis
* OCA Organized Crime Agency of British Columbia (Canada)
* OCA Optimum Currency Area
* OCA Oracle Certified Associate
* OCA Operational Control Authority
* OCA Optical Channel Analyzer
* OCA Operational Command Authority
* OCA Ontario Citizens' Assembly
* OCA Ontario College of Art
* OCA Ontario Comprehension Assessment (Canada)
* OCA Ontario Court of Appeal (Canada)
* OCA Open Content Alliance
* OCA Outstanding Cash Advance
* OCA Outstanding Chapter Award (various organizations)
* OCA Oxygen Compatibility Assessment (US NASA)
* OCA oculocutaneous albinism.