The Diwan Mosque (; also spelled Diouane Mosque) is a mosque in Fez, Morocco. It was founded by the Alawi sultan Moulay Slimane during his reign between 1792 and 1822. It is located in the center of Fes el-Bali (the old city), on Diwan Street (Rue Diwan), just north of Tala'a Kebira near its eastern end. It is one of the neighbourhood Friday mosques of the city.