Obsessive-compulsive syndrome

Overhead contact system

Old Church Slavonic

Organized Crime Section of the Ontario Provincial Police.

Ocean Colour Scene

Owls Crime Squad, Sheffield Wednesday Football Firm (a Hooligan firm)

Online Consultation Service (telemedicine)

Office of Community Services

OCS is a three letter acronym (or TLA) that may stand for:

Carbonyl sulfide

Outer Continental Shelf, maritime federal lands beyond the jurisdiction of the U.S. States.

OCS Inventory ("Open Computer and Software", [1]), an application designed to help a network or system administrator keep track of computer configuration and software installed on the network.

The Ohsees (formerly the OCS), an experimental rock band.

Odebrecht Administradora Corretora de Seguros. Lda., an Odebrecht subsidiary.

Open Conference Systems, open-source conference management software

Old Cornwall Society

Officer Cadet School or Officer Candidate School, a training establishment in many countries where military officers are trained

Original Chip-Set or "old chipset" (Commodore Amiga)

Office Communications Server, a Microsoft software product

Owl Correspondence School, the alma mater of X the Owl from the The Neighborhood of Make-Believe in the TV series Mister Rogers' Neighborhood