The Liturgy of the Presanctified Gifts, or simply (if ungrammatically) Presanctified Liturgy, is an Eastern Orthodox liturgical service for the celebration of the Eucharist on the weekdays of Great Lent. Since it is not appropriate to celebrate the joyful Divine Liturgy of Saint John Chrysostom during this penetential season, the Presanctified Liturgy is celebrated in its place. It combines Vespers with a communion service; the Eucharist which is given out consists of the Eucharistic Bread (consecrated at the previous Sunday's Divine Liturgy) mixed with un-consecrated wine. Although it is possible to celebrate this service on any weekday of Great Lent, common parish practice is to celebrate it only on Wednesdays and Fridays.

The Liturgy of the Presanctified Gifts was first documented by Gregory Dialogus, who was the papal legate to Constantinople. At one time it was supposed that he had come up with the idea himself, but now it is generally

This Liturgy is also mentioned in the Canons of the seventh century Quinisext Council:

On all days of the holy fast of Lent, except on the Sabbath, the Lord's Day, and the holy day of the Annunciation, the Liturgy of the Presanctified is to be served (Canon 52,692).

Although the Liturgy of the Presanctified Gifts is associated primarily with the Orthodox Churches and the Byzantine Rite Catholics, the concept has spread to other Churches.

Thus, for instance, there is a similar penitential rite used by the Roman Catholic Church on Good Friday, officially called the rite of Comemoration of the Lord's Passion, but informally known, especially among Catholics who celebrate the Liturgy in accordance with the Tridentine discipline, as Mass of the Pre-Sanctified. It should be noted, however, that, because there is no consacration of the gifts in that Liturgy, it is not thechnically a Mass.