CASI or Casi may refer to:

  • Center for the Advanced Study of India, a center at the University of Pennsylvania
  • Canadian Association of Snowboard Instructors
  • The Canadian Aeronautics and Space Institute
  • Club Atl├ętico San Isidro, a rugby club in San Isidro, Bueno Aires, Argentina
  • Computer-assisted self interviewing
  • Continental Air Services, Inc, an airline
  • Casi, also chashi, hilltop forts of the Ainu
  • The Cognitive Abilities Screening Instrument
  • "Casi" (song), a 2003 song by Soraya