Diomedes (/ˌdaɪəˈmiːdiːz/ or /ˌdaɪˈɒmɪdiːz/) or Diomede (/ˈdaɪəmiːd/;Greek: Διομήδης Diomēdēs "God-like cunning, advised by Zeus") is a hero in Greek mythology, known for his participation in the Trojan War.
He was born to Tydeus and Deipyle and later became King of Argos, succeeding his maternal grandfather, Adrastus. In Homer's Iliad Diomedes is regarded alongside Ajax as one of the best warriors of all the Achaeans (behind only Achilles in prowess). Later, he founded ten or more Italian cities. After his death, Diomedes was worshipped as a divine being under various names in Italy and also in Greece.