Archduke Louis, Prince Royal of Hungary and Bohemia and Prince of Tuscany (Louis Joseph Anton Johann; 13 December 1784 – 21 December 1864), was the 15th child of Holy Roman Emperor Leopold II, King of Hungary and Bohemia, Grand Duke of Tuscany, and Infanta Maria Luisa of Spain. He retired after the revolution of 1848 and lived quietly until his death in 1864 in Vienna being the last surviving child of Leopold II.