Passion Sunday is the sixth and last Sunday of Lent and the Sunday before Easter.

This is the Sunday on which palms are distributed to the congregation in most Christian churches and, because of the distribution of palm branches, it has long been called Palm Sunday. In the past, the fifth Sunday of Lent (the Sunday before Palm Sunday) was known as Passion Sunday in the Catholic and Anglican churches. However, following Vatican II, the sixth Sunday of Lent was officially re-named Passion Sunday in the Catholic and Anglican churches. Palm branches are still distributed but the focus is on the betrayal, arrest, suffering and crucification of Jesus rather than on his triumphal entry into Jerusalem just before his death. Passion/Palm Sunday is the start of Holy Week in which the Church commemorates the Last Supper and the first Eucharist on Holy Thursday and Christ's death on Good Friday.

Catholic and many Protestant churches now refer to the sixth Sunday in Lent as Passion Sunday and focus on the passion of Christ in their liturgies for that Sunday. However, customs and traditions die hard and many lay people continue to think of and refer to the sixth Sunday of Lent as Palm Sunday. While the changes to the liturgy and the re-focusing on Christ's suffering and death have been well received by the members of most congregations, the name change to Passion Sunday has not really taken root among them.

In some towns in the north of England and parts of Scotland there is an old tradition among Catholics and possibly Anglicans, of referring to Passion Sunday as Carling Sunday due to the custom of eating carlings which are peas that have been soaked over night in water or, in some communities, salt water, then fried in butter and seasoned. The seasoning in some places is pepper and salt while in others vinegar, sugar and/or rum can be added to them.

Traditionally, Carling Sunday was the fifth Sunday of Lent but, in many communities it is being moved to the sixth Sunday by many people.

As to the origin of this custom, accounts differ. Some accounts attribute the origins of the custom to a famine in Newcastle in olden times. A ship carrying food to help relieve the famine ran aground off the coast and broke up. A few days later its cargo of peas washed ashore and crowds flocked to the beach to recover them. To commemorate the event people began the annual custom of serving peas soaked in salt water. Another account says that the custom originated in ancient times when people ate peas in remembrance of the dead. Like other pre-Christian customs it was eventually absorbed by Christianity and became a Passion Day tradition.