OEC may refer to: Finance The Observatory of Economic Complexity, a data visualization site Ordre des Experts-Comptables, French association of chartered accountants Transportation Orion Expedition Cruises, Australian based luxury expedition cruise line Otis Elevator Company, an American company that manufactures vertical transportation systems Osborn Engineering Company, known as OEC, an historic British former manufacturer of motorcycles Other Offshore Energy Center, sponsor of the Ocean Star Offshore Drilling Rig & Museum in Galveston, Texas, United States Old Earth creationism, a term for several types of creationism Olfactory ensheathing cells, a type of glial cell found in the nervous system Oregon Environmental Council, an American environmental organization Orissa Engineering College, a technical institution in Bhubaneswar, Orissa, India Outdoor Emergency Care, a course for certification of first aid in non-urban situations Oxford English Corpus, an English text corpus Oxygen evolving complex, a water oxidizing enzyme .OEC, the file format for OE-Cake!, a fluid physics software application