Great Mosque of Nablus (Arabic: جامع نابلس الكبير‎ Jami' Nablus al-Kebir) is the oldest and largest mosque in the Palestinian city of Nablus. It was originally built as a Byzantine church and was converted into a mosque during the early Islamic era. The Crusaders transformed it into a church in the 11th century, but it was reconsecrated as a mosque by the Ayyubids in the 12th century. The mosque is located at the intersection of the main streets of the Old City, along the district's eastern edges.