UO may stand for:
Arts and entertainment Call of Duty: United Offensive, an expansion pack for the popular first-person shooter computer game, Call of Duty Ultima Online, a graphical massively multiplayer online role-playing game Underoath, an American Christian metalcore band from Tampa, Florida Urge Overkill, an alternative rock band, formed in Chicago, United States
Businesses and organizations Businesses Universal Orlando, a theme park resort in Orlando, Florida Urban Outfitters, a publicly traded American company Hong Kong Express Airways (IATA code: UO), an airline based in Hong Kong
Universities University of Okara, a public university in Okara, Punjab, Pakistan University of Oregon, a public research university in Eugene, Oregon, USA University of Osnabrück, public university in Osnabrück, Lower Saxony, Germany University of Otago, a public university in Dunedin, New Zealand University of Oradea, a public university in Oradea, Romania University of Ottawa, a public university in Canada University of Oxford, a public university in United Kingdom
Other organizations Orthodox Union, a kosher certification service which places a "U inside O" logo on food packaging
Other uses Unexploded ordnance, explosive weapons that did not explode when they were employed Urate oxidase, an enzyme that catalyzes the oxidation of uric acid to 5-hydroxyisourate
See also U of O (disambiguation)