The ICAO (International Civil Aviation Organization) 4-letter airport identifier codes uniquely identify individual airports worldwide. they are used in flight plans to indicate departure, destination and alternate airfields, as well as in other professional aviation publications.

Usually, the first two letters of ICAO codes identify the country. In the continental USA, however, codes normally consist of a 'K' followed by the airport's IATA code.

There are 4273 ICAO codes listed on the Airport Technology Web site.

To view an alphabetical list of ICAO codes, click on the appropriate letter below.