San Giovanni di Fassa (in ladin: Sèn Jan) is a comune (municipality) in Trentino in the northern Italian region Trentino-Alto Adige/Südtirol. It was formed on 1 January 2018 after the merger of the former comuni of Pozza di Fassa and Vigo di Fassa. It is one of I Borghi più belli d'Italia ("The most beautiful villages of Italy").