SDI is an abbreviation for:

  • Saidor airport in Saidor, Papua New Guinea after the IATA code
  • Naturally aspirated diesel with direct injection, naturally aspirated see, designation at Volkswagen for this design
  • Scuba Diving International, a diving association
  • Selective Dissemination of Information, an automatic profile service for the permanent monitoring of interesting information, see Alert Service
  • Serial Digital Interface, an interface for the serial transmission of digital audio and video data
  • Silt Density Index, a scale for existing in the water colloids
  • Single Document Interface, a special dialog application in graphical user interfaces
  • Socialisti Democratici Italiani, Italian Social Democratic Party
  • Spatial Data Infrastructure, see Spatial Data Infrastructure
  • Language and Interpretation Institute in Munich, an academy and vocational school
  • Stand Density Index, a Bestandsdichtemaß in forestry
  • Strategic Defense Initiative, an announced by U.S. President Ronald Reagan space-based missile defense system from the 1980s
  • System - dynamic intervention, a model of family constellations

S.D.I. is an abbreviation for:

  • SDI, a former Osnabrück speed metal band
  • Disambiguation
  • Abbreviation