Frederick Augustus may refer to: Frederick I, Holy Roman Emperor (1122–90), better known as Frederick Barbarossa Frederick Augustus, Duke of Württemberg-Neuenstadt (1654–1716) Frederick Augustus I, Elector of Saxony (1670–1733), better known as King Frederick August II of Poland Frederick Augustus II, Elector of Saxony (1696–1763) better known as King August III of Poland Frederick Augustus I of Oldenburg (1711–1785) Frederick Augustus, Prince of Anhalt-Zerbst (1734–93) Frederick Augustus, Duke of Nassau (1738–1816) Frederick Augustus, Prince of Brunswick-Wolfenbüttel-Oels (1740–1805) Frederick Augustus III, Elector of Saxony (1750–1827), who then became King Frederick Augustus I of Saxony Frederick Augustus, Count of Erbach-Fürstenau (1754–1784) Prince Frederick, Duke of York and Albany (1763–1827), son of George III of the United Kingdom Frederick Augustus II of Saxony (1797–1854) Frederick Augustus II, Grand Duke of Oldenburg (1852–1931) Frederick Augustus III of Saxony (1865–1932), last king of Saxony See also Augustus (disambiguation) Ernest August