COO may refer to: * Country of origin * Certificate of origin, used in international trade * Chief operating officer or chief operations officer, high ranking corporate official * Cell of origin (telecommunications) * Carboxylate, type of anion * Cobalt(II) oxide, chemical with formula of CoO. * Cadjehoun Airport (IATA Code: COO), in Cotonou, Benin * Calgary Olympic Oval, Canadian ice rink * coo, the call of pigeons * Summer Days with Coo, a 2007 Japanese animated film