Achaeans are the inhabitants of Achaea in Greece. However, the meaning of Achaea changed during the course of Ancient history, and thus Achaeans may refer to:
- Achaeans (Homer), a name used by Homer in the Iliad for Mycenaean-era Greeks in general.
- Achaeans (tribe), one of the major tribes of Greece according to the Hesiodic foundation myth
- Achaea Phthiotis, a region of ancient Thessaly
- Achaea, the modern Greek administrative unit