The Mosque of Omar is the oldest mosque in the old city of Bethlehem, located in Manger Square, near the Church of the Nativity.

The mosque is named after Omar (Umar) ibn al-Khattab (c. 581–644), the second Rashidun Muslim Caliph. Having conquered Jerusalem, Omar had traveled to Bethlehem in 637 CE to issue a law that would guarantee respect for the shrine and safety for Christians and clergy. Only four years after the death of the Islamic prophet Muhammad, Omar reportedly prayed at the location of the mosque.

The mosque was built in 1860, but did not experience renovation until 1955, during Jordanian control of the city. The land used for its construction was donated by the Greek Orthodox Church.  In the past, before the advent of light bulbs, it was common for Muslims and Christians in Bethlehem to offer olive oil to light up the surroundings of the mosque, evidence of religious coexistence in the city.