OP or Op may refer to:
Arts and entertainment
Music, television, literature, and gaming
Op., short for opus number, used to denote one work of musical composition from many OP, an abbreviated term for opening theme songs in anime One Piece, a 1997 Japanese manga and anime Out of print, a status of a book title at a publishing house Optimus Prime, a character from the Transformers franchise Overpowered (game balance), in video games, when a particular aspect or character is lacking game balance
Theater Opposite prompt, a stage right prompt corner on a theatre stage Original pronunciation, the phonology of Early Modern English, as used in William Shakespeare's time, specifically when used to perform his works in modern times.
Drinks
Orange Pekoe, a grade of black tea O.P. Anderson, a Swedish spirit of the aquavit type
Business and government
Ocean Pacific, a retail clothing company OP Financial Group, a Finnish company Operational planning, the process of planning short term measures in a company Oborový podnik ("specialized business"), a bygone Czechoslovak state designation for a business entity Publications Office of the European Union (), interinstitutional body of the European Union Odisha Police, police patrol in Odisha, India
Places
Orchard Park, New York Overland Park, Kansas
Religion and education
Order of Preachers (, Dominican Order) a Catholic religious order Oratory Preparatory School, in New Jersey, United States Old Pauline, the term for a former pupil of St Paul's School, London Old Peterite, the term for a former pupil of St Peter's School, York Overall Position, the grade appointed to Queensland high-school graduates
Science, mathematics, and technology
Organophosphate, the general name for esters of phosphoric acid Op (statistics), a symbol used in probability mathematics Octagonal prism
Computing Original post (or poster), the opening entry (or author thereof) in a thread or discussion in an internet forum Op, an abbreviated form of operator, or sysop, a user with administrative rights in multi-user computer systems Over-provisioning, a phenomenon associated with solid state storage; see
Other uses Open Philanthropy, research and grant making foundation Observation post, a position from which soldiers can watch enemy movements Opportunity point, a tennis term for an opportunity to potentially break serve when the score is 15–30
See also Op-amp, short for operational amplifier Op-ed, a newspaper opinion piece Operation (disambiguation) Operator (disambiguation) OPS (disambiguation) Ops (disambiguation) Op. cit., opere citato, or "in the work cited" 0P (disambiguation) (zero p)