OP

OP or Op may refer to:

Arts and entertainment

 * One Piece, a 1997 Japanese manga and anime
 * OP, an abbreviated term for opening theme songs in anime
 * Opposite prompt, a stage right prompt corner on a theatre stage
 * Optimus Prime, a character from the Transformers franchise
 * Op., short for opus number, used to denote one work of musical composition from many
 * 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.
 * Out of print, a status of a book title at a publishing house

Businesses and organizations

 * Operational planning, the process of planning short term measures in a company
 * OP Financial Group, a Finnish company
 * Oborový podnik ("specialized business"), a bygone Czechoslovak state designation for a business entity
 * Ocean Pacific, a retail clothing company
 * Oratory Preparatory School, in New Jersey, United States
 * Dominican Order (Ordo Praedicatorum), a Catholic religious order
 * Odisha Police, police patrol in Odisha, India
 * Publications Office of the European Union (Office des publications de l'Union européenne), interinstitutional body of the European Union

Internet

 * Original post (or poster), the opening entry (or author thereof) in a thread or discussion in an internet forum
 * Overpowered (game balance), in video games, when a particular aspect or character is lacking game balance

Mathematics and computers

 * Op (statistics), a symbol used in probability mathematics
 * Octagonal prism
 * Over-provisioning, a phenomenon associated with solid state storage; see

Places

 * Orchard Park, New York
 * Overland Park, Kansas
 * O'Brien Peak
 * O'Cain Point
 * O'Connor Peak
 * O'Donnell Peak
 * O'Fallon Park
 * O'Higgins Park
 * O'Leary Peak
 * O'Neal Point
 * O'Neill Peak
 * O'Neill Point
 * O'Neill Regional Park
 * O'Shea Peak
 * O'Sullivan Peak

Other uses

 * Observation post, a position from which soldiers can watch enemy movements
 * Old Pauline, an ex-pupil of St Paul's School, London
 * Old Peterite, a former pupil of St Peter's School, York
 * Orange Pekoe, a grade of black tea
 * Organophosphate, the general name for esters of phosphoric acid
 * Overall Position, the grade appointed to Queensland high-school graduates
 * O.P. Anderson, a Swedish spirit of the aquavit type
 * Opportunity point, a tennis term for an opportunity to potentially break serve when the score is 15–30