DDO stands for:

  • David Dunlap Observatory Catalogue, a catalog of the David Dunlap Observatory of the dwarf galaxies
  • Deputy Director for Operations, former name of the head of covert operations within the Central Intelligence Agency (now the National Clandestine Service Director of the )
  • German disc jockey organization, in 1963 founded company
  • German Druid Order, 1872, was established club
  • Dollard -des- Ormeaux, Canadian city in Quebec
  • Dungeons and Dragons Online, an online computer game
  • Ddo. , de date, from the date.
  • Disambiguation
  • Abbreviation