The Lenaia (Ancient Greek: Λήναια) was an annual Athenian festival with a dramatic competition. It was one of the lesser festivals of Athens and Ionia in ancient Greece. The Lenaia took place in Athens in Gamelion, roughly corresponding to January. The festival was in honour of Dionysus Lenaios.
"Lenaia" probably comes from "lenos" 'wine-press' or from "lenai", another name for the Maenads (the female worshippers of Dionysus).
The Lenaia is depicted on numerous vases, which show both typical Maenad scenes and those of aristocrats and wine-mixing rituals. It is unknown exactly what kind of worship occurred at the festival, but it may have been in honor of Dionysus as a youth or the rebirth of Dionysus after his murder by the Titans. It may have also had some connection with the Eleusinian Mysteries, as some of the same religious officials were involved (such as the Archon basileus and the epimeletai). These officials led the procession (πομπή pompe), which probably ended with a sacrifice.
In Athens, the festival was originally held in the Lenaion (possibly a theatre outside the city or a section of the Agora) but probably moved to the Theatre of Dionysus by the mid-fifth century. Beginning in the second half of the 5th century BCE, plays were performed (as they were at the City Dionysia festival later in the year). The audiences for the Lenaia were usually limited to the local population, since travel by sea at that time of year was considered unsafe. Metics, however, were apparently allowed to both participate and act as choregoi. Around 442 BCE, new comic contests were officially included in the Lenaia, though plays may have been performed there earlier on an informal basis. At first, the festival held dramatic competitions only for comedy, but in 432 BCE a tragic contest was introduced. Many of Aristophanes' plays were first performed there, such as 'Knights'. As with the competition at the City Dionysia, five comedies usually competed (except during the Peloponnesian War when only three were staged). When the contest for tragedy was introduced, two tragedians competed, each presenting two plays. No contests for satyr plays, nor for the singing and dancing of dithyrambs, were included. Towards the end of the century, the festival's plays were performed in the Theatre of Dionysus (though it is unclear when this location was first used). It is unknown when the Lenaia was abandoned, but contests of some sort continued into the 2nd century BCE.