Gran Mezquita de Mahdía

The Great Mosque of Mahdia stands on the southern side of the peninsula that holds the old city of Mahdia, Tunisia. It belongs to Fatimid architecture and was founded as the main mosque of the new city. Its qibla wall rests against the city's sea wall, which gives the building a fortress-like appearance. Today it has two parts: a fully renewed prayer hall with its eastern and western aisles, and a northern portico and façade that keep their original form from the time of foundation. The mosque is a listed monument of Tunisia.

Construction began in 916, after the Fatimid caliph Abdallah al-Mahdi founded the city of Mahdia. Most of the Fatimid-era city has since disappeared.

Because the qibla wall adjoins the sea wall, waves battered the building until the old mihrab cracked. The surviving remains of the mihrab show that the mosque was burned, demolished and rebuilt several times.

The present mosque was largely reconstructed by archaeologists in the 1960s, with the entrance façade the one element kept in its original state. After Tunisian independence, various improvements were made, including a minbar fitted with inscriptions and decoration.