The Anthesteria (; Ancient Greek: Ἀνθεστήρια [antʰestέːri.a]) was one of the four Athenian festivals in honor of Dionysus. It was held each year from the 11th to the 13th of the month of Anthesterion, around the time of the January or February full moon. The three days of the feast were called Pithoigia, Choës, and Chytroi.

It celebrated the beginning of spring, particularly the maturing of the wine stored at the previous vintage, whose pithoi were now ceremoniously opened. During the feast, social order was interrupted or inverted, the slaves being allowed to participate, uniting the household in ancient fashion. The Anthesteria also had aspects of a festival of the dead: either the Keres (Κῆρες) or the Carians (Κᾶρες) were entertained, freely roaming the city until they were expelled after the festival. A Greek proverb, employed of those who pestered for continued favors, ran "Out of doors, Keres! It is no longer Anthesteria".