The Lity or Litiyá (Greek: Λιτή(Liti), from litomai, "a fervent prayer") is a festive religious procession, followed by intercessions, which augments great vespers (or, a few times a year, great compline) in the Eastern Orthodox and Byzantine Catholic churches on important feast days (and, at least according to the written rubrics, any time there is an all-night vigil). Following a lity is another liturgical action, an artoklasia, and either of these terms may be used to describe both liturgical actions collectively.

At vespers, after the Prayer at the Bowing of Heads, the procession commences: the clergy, including a deacon with a censer and, when logistically possible, the chanters, the process to the narthex of the church during which are sung stichera of the feast and/or of the patron of the church. Once the procession reaches the narthex and the stichera have been sung, the deacon begins a series of lengthy petitions (these are the "lity" proper), asking for the intercession of many saints, and praying for the church and the world:

...For the salvation of the people; for the [governmental authorities]; for the clergy; for all afflicted Christian souls desirous of aid; for this city, the country and all Christians living therein; for our deceased fathers and brethren; for deliverance from famine, epidemics, earthquake, flood, fire, the sword, the invasion of barbarians and civil strife....".

"Lord, have mercy" (kyrie eleison) is sung multiple times after each petition, and this is followed by the priest reciting a prayer summarizing the petitions.

After this, the priests and deacons proceed to the artoklasia table which will have been placed in the center of the nave, all others return to their usual places, and vespers continues as usual with the Aposticha (even if the Lity is celebrated in conjunction with compline, the services ends as vespers).

Occasionally the lity is held outdoors. In places it is the custom to process around the church, the first and fifth intercessions being sung in front of the entrance and the other three intercessions being sung at each of the other three sides. For special festivity or on other occasions, e.g., or in times of public calamity, the lity may be held in fields (in case of famine) or in public squares or city halls, in which instance the procession that otherwise would be to the narthex of the church continues to wherever the lity is held.

After the lity the priests and deacons go to the middle of the church to a table prepared beforehand with five loaves of leavened bread, the artoklasia loaves, bottles of wine and olive oil and, in the Russian tradition, also a dish containing wheat kernels.

While the apolytikia (dismissal hymns) are sung — and the rubrics always mandate exactly three such hymns when there is a lity — the deacon circles the artoklasia table, censing the offerings thereon, during each, three times in all. Thereafter the priest uncovers his head and takes up one of the five loaves in his right hand, while he says the prayer: