Flenucleta was an ancient Berber, Roman and Byzantine civitas located in the Mediterranean hinterland of what was then the province of Mauretania Caesariensis. It was situated in present-day northern Algeria. The exact location of the city is unknown. Flenucleta was also the seat of the Catholic Church diocese of Flenucleta which goes back to a Roman era bishopric in the ancient town of the same name. Although the diocese ceased to effectively function with the Muslim conquest of the Maghreb, the diocese has been re-established in name at least as a titular see of the Roman Catholic Church.