Apollo: Apollo (Attic, Ionic, and Homeric Greek: , Apollōn (gen.: ); Doric: , Apellōn; Arcadocypriot: , Apeilōn; Aeolic: , Aploun; ) is one of the most important and complex of the Olympian deities in ancient Greek and Roman religion, Greco–Roman Neopaganism, and Greek and Roman mythology.