The nativity of Jesus, nativity of Christ, birth of Christ or birth of Jesus is described in the biblical gospels of Luke and Matthew. The two accounts agree that Jesus was born in Bethlehem in Judea, his mother Mary was betrothed to a man named Joseph, who was descended from King David and was not his biological father, and that his birth was caused by divine intervention.

The nativity is the basis for the Christian holiday of Christmas on December 25, and plays a major role in the Christian liturgical year. Many Christians traditionally display small manger scenes depicting the nativity in their homes, or attend Nativity Plays or Christmas pageants focusing on the nativity cycle in the Bible. Elaborate nativity displays called "creche scenes", featuring life-sized statues, are a tradition in many continental European countries during the Christmas season.

Christian congregations of the Western tradition (including the Catholic Church, the Western Rite Orthodox, the Anglican Communion, and many other Protestants, such as the Moravian Church) begin observing the season of Advent four Sundays before Christmas. Christians of the Eastern Orthodox Church and Oriental Orthodox Church observe a similar season, sometimes called Advent but also called the "Nativity Fast", which begins forty days before Christmas. Some Eastern Orthodox Christians (e.g. Greeks and Syrians) celebrate Christmas on December 25. Other Orthodox (e.g. Copts, Ethiopians, Georgians, and Russians) celebrate Christmas on (the Gregorian) January 7 (Koiak 29 on the Coptic calendar) as a result of their churches continuing to follow the Julian calendar, rather than the modern day Gregorian calendar. The Armenian Apostolic Church however continues the original ancient Eastern Christian practice of celebrating the birth of Christ not as a separate holiday, but on the same day as the celebration of his baptism (Theophany), which is on January 6.

The artistic depiction of the nativity has been an important subject for Christian artists since the 4th century. Artistic depictions of the nativity scene since the 13th century have emphasized the humility of Jesus and promoted a more tender image of him, a major change from the early "Lord and Master" image, mirroring changes in the common approaches taken by Christian pastoral ministry during the same era.

The Gospels of both Matthew and Luke place the birth of Jesus in Bethlehem. The Gospel of Luke states that Mary gave birth to Jesus and placed him in a manger “because there was no place for them in the inn". The Greek word kataluma may be translated as either “inn” or “guestroom”, and some scholars have speculated that Joseph and Mary may have sought to stay with relatives, rather than at an inn, only to find the house full, whereupon they resorted to the shelter of a room with a manger. Although Matthew does not explicitly state Joseph's place of origin or where he lived prior to the birth of Jesus, the account implies that the family lived in Bethlehem. Luke 1:26–27 states that Mary originally lived in Nazareth at the time of the Annunciation, before the birth of Jesus in Bethlehem.

In the 2nd century, Justin Martyr stated that Jesus had been born in a cave outside the town, while the Protoevangelium of James described a legendary birth in a cave nearby. The Church of the Nativity inside the town, built by St. Helena, contains the cave-manger site traditionally venerated as the birthplace of Jesus, which may have originally been a site of the cult of the god Tammuz. In Contra Celsum 1.51, Origen, who from around 215 travelled throughout Palestine, wrote of the "manger of Jesus".

The date of birth for Jesus of Nazareth is not stated in the gospels or in any secular text, but a majority of scholars assume a date between 6 BC and 4 BC. The historical evidence is too ambiguous to allow a definitive dating, but the date has been estimated through known historical events mentioned in the Gospels of Luke chapter 2 and Matthew or by working backwards from the estimated start of the ministry of Jesus. Luke 2:1 states that Jesus was born during the census of Quirinius in 6 AD, but most scholars have concluded that Luke is in error.

Like the Christian Gospels, Islam places the virgin birth of Jesus in Bethlehem