In ancient Greece, the symposium (Greek συμπόσιον symposion, from συμπίνειν sympinein, "to drink together") was a drinking party. Literary works that describe or take place at a symposium include two Socratic dialogues, Plato's Symposium and Xenophon's Symposium, as well as a number of Greek poems such as the elegies of Theognis of Megara. Symposia are depicted in Greek and Etruscan art that shows similar scenes.

The equivalent in Roman society is the Latin convivium.

The Greek symposium was a key Hellenic social institution. It was a forum for men of good family to debate, plot, boast, or simply to revel with others. They were frequently held to celebrate the introduction of young men into aristocratic society. Symposia were also held by aristocrats to celebrate other special occasions, such as victories in athletic and poetic contests.

Symposia were usually held in the andrōn (ἀνδρών), the men's quarters of the household. The participants, or "symposiasts", would recline on pillowed couches arrayed against the three walls of the room away from the door. Due to space limitations the couches would number between seven and nine, limiting the total number of participants to somewhere between fourteen and twenty seven (Oswyn Murray gives a figure of between seven and fifteen couches and reckons fourteen to thirty participants a "standard size for a drinking group"). If any young men took part they did not recline but sat up.