Critias (//; Greek: Κριτίας, Kritias; 460 BC – 403 BC) was an ancient Athenian political figure and author. Born in Athens, Critias was the son of Callaeschrus and a first cousin of Plato's mother Perictione, and became a leading and violent member of the Thirty Tyrants. He was an associate of Socrates, a fact that did not endear Socrates to the Athenian public.
After the fall of Athens to the Spartans, Critias, as one of the Thirty Tyrants, blacklisted many of its citizens. Most of his prisoners were executed and their wealth was confiscated.
Critias was killed in a battle near Piraeus, the port of Athens, between a band of pro-democracy Athenian exiles led by Thrasybulus and members and supporters of the Thirty, aided by the Spartan garrison. In the battle, the exiles put the oligarchic forces to flight, ending the rule of the Thirty.
The Critias character in Plato's dialogues Timaeus and Critias is often identified as the son of Callaeschrus – but not by Plato. Given the old age of the Critias in these two dialogues, he may be the grandfather of the son of Callaeschrus.
- Davies, J. K. (1971). Athenian propertied families 600-300 BC. London: Oxford University Press.
- Nails, D. (2002). The People of Plato: A Prosopography of Plato and Other Socratics. Cambridge: Hackett Publishing.
- Rosenmeyer, Thomas G. (1949). "The family of Critias". American Journal of Philology (The Johns Hopkins University Press) 70 (4): 404–410. doi:10.2307/291107. JSTOR 291107.