Euthydemus () may refer to:
People Euthydemus, a fleet commander for Athens during the Sicilian Expedition, 415 to 413 BC Euthydemus of Chios, a 5th-century BC sophist who features in Plato's dialogue Euthydemus Euthydemus, a son of Cephalus, mentioned in Plato's Republic Euthydemus, a son of Diocles, mentioned in Xenophon's Memorabilia Euthydemus I, 3rd century BC ruler of the Greco-Bactrian Kingdom Euthydemus II, 2nd century BC ruler of the Greco-Bactrian Kingdom Euthydemus (tyrant), 3rd century BC tyrant of Sicyon
Dialogues Euthydemus (dialogue), a dialogue by Plato