Siminina, was a Roman era civitas of the Roman province of Africa Proconsularis.The ancient city is tentatively identified with ruins at Bir-El-Djedidi, Tunisia.
The city was also the seat of an ancient Christian bishopric, suffragan of Archdiocese of Carthage. Only two bishops of Siminina are documented
Today Siminina survives as a titular bishopric and the bishop until his death was Robert Patrick Maginnis of Philadelphia.