The Fethiye Mosque is located in Its Kale, the inner castle in the walled city of ancient Ioannina. It was built immediately after the conquest by the Ottomans in 1430, near the ruins of an early 13th-century Byzantine church. Originally it was a wooden structure, which was replaced in 1611 by a stone building.

The mosque was extensively remodeled in 1795 by Ali Pasha, an Albanian born cruel despot, who made it the main mosque of his palace. The tomb of Ali Pasha and his family is located before the mosque, protected by a solid metal fence.

The mosque has a square plan, with a minaret at the western corner. The prayer hall, covered with a hemispherical dome, has a wooden balcony supported on stone columns. Interior decoration is preserved and the mihrab is particularly striking.

Nowadays the mosque is part of the Byzantine Museum and can be visited.