The Argonauts were the heroes who sailed with Jason on the Argo, in quest of the Golden Fleece. They are often called the "Minyans," because of the tribe and region from which Jason came, but many of them came from other parts of the Greek world.
According to Apollonius of Rhodes, 55 men accompanied Jason; Apollodorus lists 43 men and one woman, and various numbers can be derived from other sources. The lists do not correspond very well, but the following are some of the more famous names mentioned: Orpheus (the greatest musician of the ancient world); Heracles (the son of Zeus, famous for his Twelve Labors); Hylas (Heracles' companion); Telamon (the father of Ajax); Peleus (the father of Achilles and the brother of Telamon); Argos (the builder of the Argo); Polydeuces and Castor (or Pollux and Castor -- known as the Dioscuri, they were the sons of Leda and Zeus, and the brothers of Helen of Troy); Meleager (who killed the Calydonian boar); Zetes and Calais (the Boreads); Theseus (who killed the Minotaur and the hero of a number of other legends); Laertes (father of Odysseus); Autolycus (son of Hermes and a master thief); Atalanta (a great huntress who was the first to wound the Calydonian boar and was beloved by Meleager).
via Encyclopedia Mythica