UO

UO may stand for:

Call of Duty: United Offensive, an expansion pack for the popular first-person shooter computer game, Call of Duty
Hong Kong Express Airways (IATA code: UO), an airline based in Hong Kong
Ultima Online, a graphical massively multiplayer online role-playing game
Underoath, an American Christian metalcore band from Tampa, Florida
Unexploded ordinance, explosive weapons that did not explode when they were employed
University of Oklahoma, a coeducational public research university located in Norman, Oklahoma, USA
University of Oregon, a public, coeducational research university in Eugene, Oregon, USA
Urate oxidase, an enzyme that catalyzes the oxidation of uric acid to 5-hydroxyisourate
Urban Outfitters, a publicly traded American company
Urge Overkill, an alternative rock band, formed in Chicago, United States

See also