Onomacritus (Ancient Greek: Ὀνομάκριτος; c. 530 – c. 480 BC), also spelled Onomacritos and Onomakritos, was a Greek chresmologue, or compiler of oracles, who lived at the court of the tyrant Pisistratus in Athens and prepared an edition of the Homeric poems.
According to Herodotus, Onomacritus induced Xerxes I, the King of Persia, by his oracular responses, to decide upon his war with Greece.
"[3] That is, Pausanias attributed to Onomacritus the telling of the myth of Dionysus's dismemberment by the Titans.
[5] Among 17th-century scholars of Orphism who were sceptical of the notion of Orpheus himself having composed the works attributed to him, the idea of Onomacritus having instead been responsible for these writings, fully or in part, was a convenient alternative.
[6] The French philologist Jean-Baptiste Souchay [fr], writing in the first half of the 18th century, belived that while the Orphic Hymns were composed by Orpheus, Onomacritus converted them into the Ionian dialect.