Palm Sunday is a commemoration of Jesus' triumphal entry into Jerusalem, coming in peace and riding on a donkey. Jesus' entry into Jerusalem coincided with the Jewish festival of Passover. He was met by crowds of followers and supporters who lined the road into the city and waved branches cut from palm trees. They laid palm fronds on the road and even laid down cloaks for Jesus to ride over. This entry into Jerusalem fulfilled the Old Testament prophecies promising that God's Messiah would enter the holy city and go to the temple.

Palm Sunday church services typically start with a procession of churchgoers carrying branches (often of willow or pussy willow) and palms. The service may include a Dramatization of the Passion. Small crosses, each made of a single palm frond, are blessed and distributed to everyone in the congregation. Additional crosses are kept until the following year when they are burned to make the ashes for Ash Wednesday observances. A few churches also maintain the ancient tradition of distributing small biscuit-like cakes, called Pax Cakes, which are marked with a lamb as a symbol of peace and goodwill. Palm fronds may be used as altar and other church decorations. Children often play a prominent role in Palm Sunday services.

In the Eastern Orthodox Church Palm Sunday is preceded by Lazarus Saturday.