In ancient Greek mythology, the Empusa (or Empousa) was a female supernatural monster or demoness. Hecate sent Empusa to harass travelers. It scared to death or ate anybody that travelled along the paths or roads it inhabited. The empusae are sometimes described as having donkey-like features.

More recent Greek tales describe the creature as a merely frightening shapeshifter, but blame it for injuring sheep.

The Empusae are similar to the lilim, and the legend of the former may be derived from that of the latter. See also Lamia.