Jakob Anton of Dietrichstein (24 July 1678 – 15 May 1721), was a German prince member of the House of Dietrichstein.
He was eighteenth child and ninth (but fourth surviving) son of Ferdinand Joseph, 3rd Prince of Dietrichstein, and Marie Elisabeth, a daughter of Johann Anton I, Prince of Eggenberg, Duke of Ceský Krumlov and Princely Count (gefürsteter Graf) of Gradisca d'Isonzo.