III. Leopold

III. Leopold can refer to:

 III. Leopold, Margrave of Austria, (1073-1136), Avusturya'nın altıncı margravı
 III. Leopold, Duke of Austria (1351-1386), co-Archduke of Austria and co-Duke of Styria
 III. Leopold, Duke of Anhalt-Dessau (1740-1817), first Duke of Anhalt-Dessau
 III. Leopold, Prince of Lippe (1821-1875)
 III. Léopold (Belçika Kralı) (1901-1983), Belçikalıların dördüncü kralı