In Greek mythology, Iasus was the name of several individuals:

• Iasus was the father of Atalanta by Clymene; he was the son of King Lycurgus of Arcadia.
• Iasus was one of the Dactyli, the son of Rhea and Anchiale .
• Iasus was the king of Argos. He was the son of either Argus (Panoptes) and Ecbasus , or Triopas and Ismene.
• Iasus was killed by Aeneas in the Trojan War.