OEC may refer to:
Businesses and organisations Offshore Energy Center, sponsor of the Ocean Star Offshore Drilling Rig & Museum in Galveston, Texas, United States Oregon Environmental Council, an American environmental organization Ordre des Experts-Comptables, French association of chartered accountants Orion Expedition Cruises, Australian expedition cruise line Orissa Engineering College, Bhubaneswar, India Otis Elevator Company, an American company that manufactures vertical transportation systems Osborn Engineering Company, known as OEC, an historic British former manufacturer of motorcycles OEConnection, an American company that provides B2B solutions, connecting Automotive Manufacturers, Dealers and Collision & Repair shops
Science and technology Olfactory ensheathing cells, in animals Oxford English Corpus, in linguistics Oxygen evolving complex, in plants .OEC, a fluid physics software file format
Other uses Odd Eye Circle, a South Korean girl group Old Earth creationism, a term for several types of creationism Outdoor Emergency Care, a course for certification of first aid in non-urban situations Overseas Employment Certificate, a Philippine identity document