Ajaccio Cathedral, officially the Cathedral of Our Lady of the Assumption of Ajaccio and also known as the Cathedral of the Assumption of Saint Mary, is a Roman Catholic church located in Ajaccio, Corsica. The cathedral is the ecclesiastical seat of the Bishop of Ajaccio, a suffragan of the Archdiocese of Marseille. It is dedicated to the Virgin Mary, and is in the Baroque/Mannerist architectural style.

Ajaccio is the capital and largest city of Corsica, France. It forms a French commune, prefecture of the department of Corse-du-Sud, and head office of the Collectivité territoriale de Corse. It is also the largest settlement on the island. Ajaccio is located on the west coast of the island of Corsica, 210 nautical miles (390 km) southeast of Marseille.