Arts and entertainment

Brands, businesses, and organizations

OC Transpo, a public transit company in Ottawa and Carleton in Ontario, Canada
Organisation Consul, a former terrorist organization active in Germany from 1920 to 1922
Oregon Crusaders Drum and Bugle Corps, a Drum Corps International group commonly abbreviated as "OC"
Ornithological Council
Owens Corning, NYSE ticker symbol
Oxi Clean, a cleaning product
Orbis Communications, a former television distribution company
PGA Express (IATA code "OC" 2001–2015)
Air California (IATA Code "OC" 1967–1987)

Oaklands College, a further education in central Hertfordshire, UK
Oakwood College, a college in northern Alabama, USA, affiliated with the Seventh-day Adventist Church
Oberlin College, a liberal arts college in Ohio
Oklahoma Christian University
Old Carthusian, one who attended Charterhouse School
Old Colchestrian, one who attended Colchester Royal Grammar School
Old Chigwellian, one who attended Chigwell School
Orewa College, a college in the North Island, New Zealand

Oak Cliff, a community in Dallas, Texas
Oakland–Alameda County Coliseum, a stadium in Oakland, California and the home of the Oakland Raiders
Oakland County, Michigan
Ocean City, Maryland, a prominent beach resort town in the mid-Atlantic region
Ocean City, New Jersey, a family-oriented seaside resort town near Atlantic City
Oceanside, California, a beachside city located within San Diego County
Oklahoma City, Oklahoma, the capital of the U.S. state of Oklahoma
Osceola, Indiana
Oregon City, Oregon, the county seat of Clackamas County, Oregon

Ottawa—Carleton (federal electoral district), a federal electoral district in Ontario, Canada
Old Colwyn, Wales

Officer of the Order of Canada, post-nominal letters for a grade within the Canadian order
Offensive coordinator, a coaching position in American and Canadian football
Officer candidate
Officer in charge (police)
Officer commanding, in military use

Oleoresin capsaicin or oleoresin capsicum, the active ingredient in pepper spray and OC gas
- OC spray, also known as pepper spray
Open collector, electrical interface. Used in data communication
openCanvas, a raster graphics software
Optical Carrier levels in the SONET fiber-optic network specification
Oral contraceptive, usually referring to the combined oral contraceptive pill
Organ-on-a-chip, microfluidic device that simulates whole physiological and mechanical organ responses
Overclocking, the process of forcing a computer component to run at a higher clock rate than it was designed for
Overcurrent, an excessive value of electric current

o.c. or op. cit., opere citato
O.C. (rapper) (born 1971), American rapper
Offering circular, in finance, for a bond offering
Order of Carmelites, a Roman Catholic order
Organized crime, in law
On-center, in construction, indicating that the distance quoted is between the centers of neighboring wall studs, joists, or other members
Original content, original character, or original contribution, used to assert one's authorship of a given subject matter
Outrigger canoe
Other Caste or Open Category, a caste designation used in governmental forms in India, usually referring to Forward Castes