DDO may refer to: Science and technology David Dunlap Observatory Catalogue, a catalogue of dwarf galaxies that was published in 1959 DDO (gene), that encodes the D-aspartate oxidase enzyme Distant detached objects, class of minor planets in the outer reaches of the Solar System Dynamic Drive Overlay, a software technique to extend a system BIOS Games Dungeons & Dragons Online, a massively multiplayer online role-playing game Titles Deputy Director for Operations, particularly as the title of a specific CIA official; cf. article The above title is sometimes incorrectly rendered as Deputy Director of Operations; especially this latter term is also in generic use as the title of officials in business or other organizations. Director of Operations, particularly in francophone environments, from the French Directeur Des Opérations. Diocesan Director of Ordinands, a priest in a Church of England diocese overseeing the ordination process Other DDO Artists Agency, a talent agency Dollard-des-Ormeaux, on-island suburb of Montreal in southwestern Quebec, Canada Tsez language, by ISO 639-3 code Den Danske Ordbog, a dictionary of Danish See also