Frederick Augustus I (or III) of Saxony (December 23, 1750 - May 5, 1827). He succeeded his father, Frederick Christian, in December 1763, as Elector Frederick Augustus III of Saxony (from the House of Wettin). For the first 5 years of his reign, his mother Dowager Electress Maria Antonia was regent. Following the abolition of the Holy Roman Empire in 1806, he became King of Saxony as Frederick Augustus I.

Frederick Augustus I was also Duke of Warsaw (1807 - 1815) (as Fryderyk August I).