Argaeus (Greek: Ἀργαῖος) or Araeus, was according to 5th-century BC Greek writer Herodotus one of six predecessors of his contemporary, king Alexander I of Macedon (r. 498–454). Alexander I's predecessors, starting from the nearest, were according to Herodotus: Amyntas, Alcetas, Aëropus, Philip I, Argaeus, and Perdiccas I. A rival tradition is held by Livy, Pausanias, Suidas and Junianus Justinus, with Caranus as the first Macedon king.
Argaeus was according to 2nd-century AD Macedonian writer Polyaenus the first king of Macedon, who tricked and won over his superior enemies (the Taulanti king Galaurus) with women dressed as men with wreaths and thyrsi (staffs), closely related to the cult of Dionysus. After the victory, Argaeus founded a temple dedicated to Pseudanor (Fake-man).
Only Alexander I's father, Amyntas, is firmly established in historical record. The eponym Argaeus for the dynasty (the Argead dynasty) was used to maintain the myth of origin from Argos. Nevertheless, regnal years have been applied to these legendary predecessors in modern literature; Argaeus has been claimed to have ruled in 678 BC.