Maria Anna Sophia of Saxony (Maria Anna Sophia Sabina Angela Franciska Xaveria; 29 August 1728 – 17 February 1797) was a daughter of King Augustus III of Poland and his wife Maria Josepha of Austria who became Electress of Bavaria.
Maria Anna was married to the Bavarian Elector Maximilian III Joseph in 1747.
Having no children of her own, Maria Anna negotiated with King Frederick II of Prussia after her husband’s death in 1777 to secure Bavaria’s independence against Austria and to support the succession rights of the Wittelsbach branch Palatinate Zweibrücken-Birkenfeld in Bavaria, when the new Elector of Bavaria Charles Theodore attempted to cede Lower Bavaria to Austria. A secret treaty with Holy Roman Emperor Joseph II had been concluded in the end. In exchange for Lower Bavaria, Charles Theodore was to receive the Austrian Netherlands (close to his ancestral domains), the Palatinate (already his patrimony), Jülich and Berg.