Millstatt Abbey (German: Stift Millstatt) is a former monastery in Millstatt, Austria. Established by Benedictine monks about 1070, it ranks among the most important Romanesque buildings in the state of Carinthia. The Benedictines were succeeded by the knightly Order of Saint George in 1469 and the Society of Jesus (Jesuits, SJ) in 1598.
Until its dissolution in 1773 under Emperor Joseph II, Millstatt Abbey for centuries was the spiritual and cultural centre of Upper Carinthia and with its possessions around Millstätter See, in the Gurk Valley (Brückl) as well as in the former March of Friuli and in the Archbishopric of Salzburg (Pinzgau), one of the largest in the region.