Aper of Toul was a fifth-century bishop who served the diocese of Toul for seven years starting in 500. Born near Trier, he may have practiced law before entering the priesthood. He was the brother of Saint Apronia and was chosen by the faithful to succeed Bishop Ursus. During his episcopate, he was noted for his generosity toward the poor and his efforts to combat paganism in rural areas, particularly in the city of Grand.