Gregory IV (died 915) is the firstborn son of Duke Sergius II of Naples and successor of his paternal uncle, Bishop Athanasius, in 898, when he is elected dux, or magister militum, unanimously by the aristocracy.
His other paternal uncle, Stephen, succeeds Athanasius as bishop.
According to the Chronicon ducum et principum Beneventi, Salerni, et Capuae et ducum Neapolis, he reigns for sixteen years and eight months.
