Saint Mary Church of the Holy Belt (Arabic: كنيسة أم الزنار; Um az-Zinnar) is a historical Syriac Orthodox Church in Homs, Syria. The church is built over an underground church dating back to 50 AD. It is the seat of the Syriac Orthodox archbishopric. The church contains a venerated relic that is supposed to be a section of the belt of Mary mother of Jesus. This is the Syriac church's equivalent of the Cincture of the Theotokos of the Greek Orthodox Church, now in Vatopedi Monastery, Mount Athos, and the Catholic Girdle of Thomas in Prato Cathedral in Italy. All are related to the same legend of the Virgin Mary giving the Apostle Thomas her belt as proof of the Dormition of the Theotokos (Assumption of Mary for the Catholic Church).
The church was used as a shield by the opposition armed groups during the 2011-2012 Syrian unrest, and was damaged during confrontations between the armed opposition and the security forces.
Later confrontations caused extensive damage to the exterior of the church.