Ernest II may refer to:
Ernest II, Duke of Swabia (died in 1030) Ernest II, Duke of Brunswick-Grubenhagen (1418–1466) Ernest II, Count of Mansfeld-Vorderort (1479–1531) Ernest II, Duke of Brunswick-Lüneburg (1564–1611) Ernest II, Duke of Saxe-Gotha-Altenburg (1745–1804) Ernest II, Duke of Saxe-Coburg and Gotha (1818–1893) Ernest II, Count of Lippe-Biesterfeld (1842–1904) Ernst II, Prince of Hohenlohe-Langenburg (1863–1950) Ernst II, Duke of Saxe-Altenburg (1871–1955) Ernest Augustus II, Duke of Saxe-Weimar-Eisenach (1737–1758) Ernest Frederick II, Duke of Saxe-Hildburghausen (1707–1745) Ernst Günther II, Duke of Schleswig-Holstein (1863–1921) Ernst Ludwig II, Duke of Saxe-Meiningen (1709–1729)