OP, O.P., or Op may refer to any of the following:
Observation post, a position from which soldiers can watch enemy movements
Ocean Pacific, a retail company based in California, USA
Orange pekoe, a term used in the Western tea trade to describe a particular grade of black teas
Orange peel, the outer layer of an orange fruit
Ordo Praedicatorum, commonly known as the Dominican Order, a Catholic religious order
Operating Procedure, a standardised working protocol
Operating Profit, a measure of business profitability
Out of print, status of a book title at a publishing house
op, slang for marijuana grow operation.
Mathematics
Operator (mathematics), in mathematics, a mapping from one vector space or module to another
Op (statistics), a symbol used in probability mathematics
Octagonal prism, is a prism formed by square sides and two regular octagon caps
Culture
Op art, also known as optical art, is a style of visual art that makes use of optical illusions
Op-ed, a newspaper opinion piece of a writer unaffiliated with the editorial board
Opposite prompt, the right side of a theatre stage
Op., abbreviation for Opus number, used to denote one work of musical composition from many
Op. cit., abbreviation for the Latin term opus citatum est, meaning "the work has been cited"
Optimus Prime, a character from the Transformers franchise
