OST may refer to:

Music

  • Original soundtrack, recorded sound accompanying a production such as a film
  • O.S.T., an alias of electronic musician Chris Douglas
  • O.S.T. (album), by the People Under the Stairs

Science and technology

  • Object Storage Target in computing, used by the Lustre file system an others
  • Oligosaccharyltransferase, an enzyme
  • Open-space technology, for organising meetings
  • Open Systems Theory, a form of sociotechnical systems pioneered by Fred Emery
  • Orbit stabiliser theorem in mathematics
  • Offline Storage Table, a Microsoft file format
  • OST Family (organic solute transporter) of genes
  • Origins Space Telescope, a space telescope mission
  • Open Source Threat, any software demonstrating a device vulnerability that is open-source

Organizations

  • Office of Science and Technology, a British government agency
  • Office of Secure Transportation, a US government agency
  • Order of the Solar Temple, French esoteric cult
  • Organisation Socialiste des Travailleurs, the Socialist Workers Organisation of Senegal
  • Outer Space Treaty, a treaty regulating international law in outer space.

Places

  • Ostend–Bruges International Airport, Belgium, IATA code
  • Old Spanish Trail (auto trail)
  • East Germany, as with the name in german Ostdeutschland

Other uses

  • Ost (game), a 1986 board game
  • Ost (surname)