The Carinthian plebiscite determines that the larger part of the Duchy of Carinthia should remain part of Austria.

The Carinthian plebiscite (German: Kärntner Volksabstimmung, Slovene: Koroški plebiscit) was held on 10 October 1920 in the area predominantly settled by Carinthian Slovenes. It determined the final southern border between the Republic of Austria and the newly formed Kingdom of Serbs, Croats and Slovenes (Yugoslavia) after World War I.