From Wikipedia, the free encyclopedia. The languages of Austria include German, the official language and lingua franca; Austro-Bavarian, the main language outside Vorarlberg; Alemannic, the main language in Vorarlberg; and several minority languages.lovene, an official language in Carinthia, is spoken by 0.3% of Austrians. Carinthian Slovenes are recognized as a minority and have enjoyed special rights following the Austrian State Treaty (Staatsvertrag) of 1955.