The Achaeans were one of the four major tribes into which the people of Classical Greece divided themselves.

According to the foundation myth formalized by Hesiod, their name comes from Achaeus, the mythical founder of the Achaean tribe, who was supposedly one of the sons of Xuthus, and brother of Ion, the founder of the Ionian tribe.

Xuthus was in turn the son of Hellen, the mythical patriarch of the Greek (Hellenic) nation.

Historically, the members of the Achaean tribe inhabited the region of Achaea in the northern Peloponnese.

Unlike the other major tribes (Ionians, Dorians and Aeolians), the Achaeans did not have a separate dialect in the Classical period, instead using a form of Doric.