Ichthyas (Greek: Ἰχθύας; fl. 4th-century BCE), the son of Metallus, was a Greek philosopher and a disciple and successor of Euclid of Megara in the Megarian school.[1] He was a colleague of Thrasymachus of Corinth in the school.[2] Ichthyas is described as a man of great eminence, and Diogenes of Sinope is said to have addressed a dialogue to him.[3]

According to Hilarius Emonds,[4] correcting a previously misread passage in Tertullian's Apologeticus, Ichthyas was a leader in the oligarchic revolt in Megara in 375 BCE.[5]


  1. ^ Diogenes Laërtius, ii. 112; Athenaeus, viii. 335; Suda, Euclides
  2. ^ Diogenes Laërtius, ii. 113
  3. ^ Diogenes Laërtius, ii. 112; cf. vi. 80
  4. ^ H. Emonds, (1937), Die Oligarchenrevolte zu Megara im Jahre 375 und der Philosoph Ichthyas bei Tertullian, Apol. 46, 16. Rh. Mus. 86, 180-191.
  5. ^ Tertullian, Apologeticum, 46, 16: "et Ichthyas, dum civitati insidias disponit, occiditur."