Eidos may refer to:
- Eidos, a Greek term meaning "form," "essence," "type," or "species". See Plato's theory of Forms and Aristotle's theory of universals.
- Square Enix Europe or Eidos plc, a British publisher of video game software
- Eidos Interactive, a British video game publisher
- Eidos Hungary, a wholly owned studio of Eidos Interactive (owned by Square Enix)
- EIDOS Arts Development Foundation, a Ukrainian organisation