ICAO code may refer to:

  • ICAO airport code, a four-character alphanumeric code designating each airport
  • ICAO airline designator, a three-letter code designating each airline
  • ICAO aircraft type designator, a three- or four-character alphanumeric code designating every aircraft type (and some sub-types) that may appear in flight planning
  • ICAO aircraft marshalling signals, visual signalling between ground personnel and pilots on an airport, aircraft carrier or helipad
  • ICAO 24-bit address, allocation of 24 bit addresses to states to uniquely identify aircraft worldwide
  • ICAO altitude code aka Gillham code, an encoding used in older aircraft to report altitudes