Louisville Muhammad Ali International Airport

Louisville Muhammad Ali International Airport carries the IATA code SDF — the three letters printed on boarding passes and baggage tags — and the ICAO code KSDF, used in flight plans and by air traffic control. It serves Louisville, United States.

IATA codes are assigned by the International Air Transport Association for passenger-facing use; the four-letter ICAO code encodes region and country and belongs to the operational side of aviation.