Otto, forby spelt Otho (Greek: Ὄθων, Βασιλεὺς τῆς Ἑλλάδος, Óthon, Vasiléfs tis Elládos; 1 Juin 1815 – 26 Julie 1867), wis a Bavarie prince wha became the first modren Keeng o Greece in 1832 unner the Convention o Lunnon.