South Tyrol is connected to the important airports in Northern Italy, Germany and Austria, and also Bolzano features a small airport
The closest important airports are 80 to 200 km away and can be reached by transfer-busses (e.g. Dolomites Airport Shuttle), by train or by car:
Innsbruck Airport
Salzburg Airport
Munich Airport
Verona Airport
Treviso Airport
Venice Airport
Milano Orio al Serio Airport
Bolzano features a small airport, further informations here: Airport Bolzano-Dolomites.