Sophocles (/ˈsɒfəkliːz/; Ancient Greek: Σοφοκλῆς, pronounced [so.pʰo.klɛ̂ːs], Sophoklễs; c. 497/496 – winter 406/405 BC) was an ancient Greek tragedian, one of three from whom at least two plays have survived in full. His first plays were written later than, or contemporary with, those of Aeschylus and earlier than, or contemporary with, those of Euripides. Sophocles wrote more than 120 plays, but only seven have survived in a complete form: Ajax, Antigone, Women of Trachis, Oedipus Rex, Electra, Philoctetes, and Oedipus at Colonus. For almost 50 years, Sophocles was the most celebrated playwright in the dramatic competitions of the city-state of Athens, which took place during the religious festivals of the Lenaea and the Dionysia. He competed in 30 competitions, won 24, and was never judged lower than second place. Aeschylus won 13 competitions and was sometimes beaten by Sophocles; Euripides won four.

The most famous tragedies of Sophocles feature Oedipus and Antigone: they are generally known as the Theban plays, though each was part of a different tetralogy (the other members of which are now lost). Sophocles influenced the development of drama, most importantly by adding a third actor (attributed to Sophocles by Aristotle; to Aeschylus by Themistius), thereby reducing the importance of the chorus in the presentation of the plot. He also developed his characters to a greater extent than earlier playwrights.

Sophocles, the son of Sophillus, was a wealthy member of the rural deme (small community) of Hippeius Colonus in Attica, which was to become a setting for his play Oedipus at Colonus. He was also probably born there, a few years before the Battle of Marathon in 490 BC: the exact year is unclear, but 497/6 is most likely. He was born into a wealthy family (his father was an armour manufacturer) and was highly educated. His first artistic triumph was in 468 BC, when he took first prize in the Dionysia, beating the reigning master of Athenian drama, Aeschylus. According to Plutarch, the victory came under unusual circumstances: instead of following the usual custom of choosing judges by lot, the archon asked Cimon, and the other strategoi present, to decide the victor of the contest. Plutarch further contends that, following this loss, Aeschylus soon left for Sicily. Though Plutarch says that this was Sophocles's first production, it is now thought that his first production was probably in 470 BC. Triptolemus was perhaps one of the plays that Sophocles presented at this festival.

In 480 BC, Sophocles was chosen to lead the paean (a choral chant to a god), celebrating the Greek victory over the Persians at the Battle of Salamis. Early in his career, the politician Cimon might have been one of his patrons, but if he was, there was no ill will borne by Pericles, Cimon's rival, when Cimon was ostracized in 461 BC. In 443/2, Sophocles served as one of the Hellenotamiai, or treasurers of Athena, helping to manage the finances of the city during the political ascendancy of Pericles. In 441 BC, according to the Vita Sophoclis, he was elected one of the ten generals, executive officials at Athens, as a junior colleague of Pericles; and he served in the Athenian campaign against Samos. He was supposed to have been elected to this position due to his production of Antigone, but this is "most improbable".

In 420 BC, he was chosen to receive the image of Asclepius in his own house when the cult was being introduced to Athens and lacked a proper place (τέμενος). For this, the Athenians gave him the posthumous epithet Dexion (receiver). But "some doubt attaches to this story". He was also elected, in 411 BC, one of the commissioners (probouloi) who responded to the catastrophic destruction of the Athenian expeditionary force in Sicily during the Peloponnesian War.

Sophocles died at the age of 90 or 91 in the winter of 406/5 BC, having seen, within his lifetime, both the Greek triumph in the Persian Wars and the bloodletting of the Peloponnesian War. As with many famous men in classical antiquity, his death inspired a number of apocryphal stories. One claimed that he died from the strain of trying to recite a long sentence from his Antigone without pausing to take a breath. Another account suggests he choked while eating grapes at the Anthesteria festival in Athens. A third holds that he died of happiness after winning his final victory at the City Dionysia. A few months later, a comic poet, in a play titled The Muses, wrote this eulogy: "Blessed is Sophocles, who had a long life, was a man both happy and talented, and the writer of many good tragedies; and he ended his life well without suffering any misfortune." According to some accounts, however, his own sons tried to have him declared incompetent near the end of his life, and he refuted their charge in court by reading from his new Oedipus at Colonus. One of his sons, Iophon, and a grandson, also named Sophocles (son of Ariston), also became playwrights.

An ancient source, Athenaeus's work Sophists at Dinner, contains references to Sophocles's sexuality. In that work, a character named Myrtilus claims that Sophocles "was partial to boys, in the same way that Euripides was partial to women" ("φιλομεῖραξ δὲ ἦν ὁ Σοφοκλῆς, ὡς Εὐριπίδης φιλογύνης"), and relates an anecdote, attributed to Ion of Chios, of Sophocles flirting with a serving-boy at a symposium:

βούλει με ἡδέως πίνειν; [...] βραδέως τοίνυν καὶ πρόσφερέ μοι καὶ ἀπόφερε τὴν κύλικα.
Do you want me to enjoy my drink? [...] Then hand me the cup nice and slow, and take it back nice and slow too.