OCS or Ocs may refer to:
Places Öcs, a village in Veszprém county, Hungary Outer Continental Shelf, a maritime federal land zone beyond the jurisdiction of the United States
Music Ocean Colour Scene, an English rock group Oh Sees, an American experimental rock band
Psychiatry and medicine Obsessive–compulsive syndrome, another name for obsessive–compulsive disorder
Science and technology Open Collaboration Services, for integration of web services and communities into desktop and mobile applications, an open and vendor-independent API Office of the Chief Scientist (Australia), a part of Department of Innovation, Industry, Science and Research Original Chip Set, used in the earliest Commodore Amiga computers Carbonyl sulfide, a chemical compound with the formula OCS Microsoft Office Communications Server, a software product OCS Inventory (Open Computer and Software Inventory), an application which inventories IT assets Online charging system, a system allowing providers of communication services to charge customers based on service usage Overhead contact system, a system which provides electric power to trains
Schools and alumni associations Officer candidate school, a training establishment in many countries where military officers are trained Oklahoma Christian School Old Cliftonian Society, the society for the alumni of Clifton College, Bristol, England Opelika City Schools, a school district headquartered in Opelika, Alabama, United States Senator O'Connor College School in Toronto, Ontario, Canada
Other uses Ontario Cannabis Store Corisco International Airport, IATA airport code "OCS" Federation of Old Cornwall Societies or sometimes OCS, a Cornish history charity OCS Group, a British facilities management business OCS (TV network), defunct French TV network Old Church Slavonic, a Slavic language which developed in the 9th century Office of Community Services, a US Federal Government agency On course side, a term meaning that a sailboat has crossed the start line of a race early Operational Combat Series, a game series from The Gamers and Multi-Man Publishing Original Chicken Sandwich, a Burger King product
See also OC (disambiguation) for the singular of "OCs"