The Archdiocese of Lille is a Roman Catholic archdiocese located in northern France. It was established in the 17th century and serves as the ecclesiastical jurisdiction for the region. The archdiocese is part of the larger Catholic Church and is responsible for overseeing various parishes and religious activities within its territory. The archdiocese is headed by an archbishop, who plays a key role in guiding the spiritual and administrative functions of the church in the area. The city of Lille serves as the archdiocesan seat, where the Basilica of Notre-Dame de la Treille is a prominent landmark and a center for worship and community events.