DDO may refer to:

Science and technology D-aspartate oxidase, encoded by the DDO gene David Dunlap Observatory David Dunlap Observatory Catalogue Distant detached object, a type of minor planet Dynamic drive overlay, a software technique to extend a system BIOS

Titles Deputy Director for Operations, of the United States Central Intelligence Agency Diocesan Director of Ordinands, in the Church of England

Other uses Dollard-des-Ormeaux, a suburb of Montreal Dungeons & Dragons Online, a massively multiplayer online role-playing game Tsez language

See also