Aldein (German: [alˈdaɪn]; Italian: Aldino [alˈdiːno]) is a comune (municipality) and a village in South Tyrol in northern Italy, located about 15 kilometres (9 mi) south of the city of Bolzano.

Aldein borders the following municipalities: Bronzolo, Montan, Deutschnofen, Auer, Truden and Ville di Fiemme.

[3] The coat of arms is divided party per fess; on the top are two quarter-circle, azure on argent background that represents the Weisshorn.

The lower part shows the argent cross of Saint Andrew shortened that represent the four original hamlets on a gules background as the mountain of porphyrite.

[4] According to the 2024 census, 97.89% of the population speak German, 1.85% Italian and 0.26% Ladin as first language.