| Acronym | Definition |
|---|
| OCS | Office Communications Server (Microsoft) |
| OCS | Officer Candidate School |
| OCS | Office of Community Services |
| OCS | Office of Career Services |
| OCS | Office of Coast Survey |
| OCS | Office of Children's Services (Alaska) |
| OCS | Ocean Colour Scene (band) |
| OCS | Occupant Classification System |
| OCS | Oklahoma Climatological Survey |
| OCS | On Course Side (sailboat racing) |
| OCS | Operator Control Station |
| OCS | Office of Cancer Survivorship (National Cancer Institute) |
| OCS | Old Church Slavonic (extinct liturgical language; aka Old Church Slavic) |
| OCS | On the Course Side (sailing, starting line) |
| OCS | Online Charging System (commerce software) |
| OCS | Online Customer Service |
| OCS | Officer Cadet School |
| OCS | Open Content Syndication (XML format) |
| OCS | Operational Control System |
| OCS | Office of the Chief of Staff (US Army) |
| OCS | Originating Call Screening |
| OCS | Office Car Special (various companies) |
| OCS | Offshore Constitutional Settlement (Australia) |
| OCS | Offensive Counterspace |
| OCS | On Campus Suspension |
| OCS | Off-Campus Student |
| OCS | Openconnect Systems |
| OCS | Obstacle Clearance Surface (aviation) |
| OCS | Office of Conference Services (various universities) |
| OCS | On-Card Sequencer |
| OCS | Obsessive-Compulsive Syndrome |
| OCS | Old Chipset (Commodore Amiga computers) |
| OCS | Ophthalmic Coding Specialist |
| OCS | On-Line Comparison System |
| OCS | Ocean Color Scanner |
| OCS | On Company Service |
| OCS | Onboard Computer System (Russian) |
| OCS | Oil Companies School (Libya) |
| OCS | Oceanic Control System (air traffic management system used by Airways Corporation of New Zealand Ltd) |
| OCS | Ojemann Cortical Stimulator (Integra) |
| OCS | Orange County Speaker (Garden Grove, CA) |
| OCS | Offering Circular Supplement (bond drafting document) |
| OCS | Offender Communication System (Digital Solutions, Inc.; correctional system inmate phone system) |
| OCS | Oldtimer Club Stokkem (automobile club; Dilsen-Stokkem, Belgium) |
| OCS | Orbit Control Subsystem |
| OCS | Officer Conducting the Serial |
| OCS | Optical Character Scanner |
| OCS | Office of the Corporate Secretary (Canada) |
| OCS | Osteopathic Clinical Skills |
| OCS | Optical Control Subsystem |
| OCS | Occupation Control System (railway) |
| OCS | Overload Control Subsystem |
| OCS | Operational Case Study |
| OCS | Office of Communication Systems |
| OCS | Office of Cyberspace Security (US White House) |
| OCS | Office of Compensatory Services (Special Education, Baltimore City Public School System) |
| OCS | One-Cylindrical Stack (capacitor with high dielectric constant) |
| OCS | Oxygen Cost Score |
| OCS | Oil Company of Spain, SA |
| OCS | Orbit Circularization System |
| OCS | Operational Capability Demonstration |
| OCS | Overhead Catenary/Collector System (transit) |
| OCS | Optical Channel States (Lucent) |
| OCS | Optical Crossconnect System |
| OCS | Office on Contract Settlement |
| OCS | Operation and Control Simulator |
| OCS | Operations Communications System |
| OCS | Optical Communications Supplement (IEEE) |
| OCS | Outstation Communication Subsystem |
| OCS | Oregon Cascade Symphony |
| OCS | Oeuvre des Colonies Scolaires (French: Works of Colony Schools) |
| OCS | Ordinary Circular Slot |
| OCS | Overhead Catenary System (power) |
| OCS | Overseas Citizens Service |
| OCS | Orthopedic Clinical Specialist |
| OCS | Order Control System |
| OCS | Overseas Courier Service |
| OCS | Oaks Christian School (Westlake Village, CA) |
| OCS | Orthogonal Curvilinear Coordinate System |
| OCS | Online Car Show (est. 2004) |
| OCS | Oral Corticosteroids |
| OCS | Oracle Collaboration Suite |
| OCS | Order Communication System |
| OCS | Optimum Class Size |
| OCS | Original Chipset (Commodore Amiga computers) |
| OCS | Orange County Supertones (band) |
| OCS | Optical Control System |
| OCS | Outer Continental Shelf |
| OCS | Overhead Contact System |
| OCS | Ordinary Common Sense |
| OCS | Outbound Contact Solution |
| OCS | Orange County Schools (North Carolina) |