Ernest III

Ernest III may refer to:


 * Ernest III, Duke of Brunswick-Grubenhagen (1518–1567)
 * Ernest III, Duke of Saxe-Hildburghausen (1655–1715)
 * Ernest III, Duke of Saxe-Coburg-Saalfeld (1784–1844)
 * Ernest Frederick III, Duke of Saxe-Hildburghausen (1727–1780)