Yes, Greek Orthodox Christians do celebrate Christmas! It is one of the most important holidays in the Orthodox Christian calendar. The date of Christmas in the Greek Orthodox Church is usually celebrated on January 6th, which is known as Theophany in the Greek Orthodox Church. Theophany is the day when the Church celebrates the revelation of God as both human and divine in the person of Jesus Christ. It is a joyous occasion filled with traditions, customs, and festivities.