Pierius was a third-century Christian presbyter and philosopher from Alexandria. He likely served as the head of the Catechetical School of Alexandria alongside Achillas during the episcopate of Theonas. Known for his expertise in preaching and biblical exegesis, he was sometimes referred to as "Origen the Younger." After surviving the Diocletianic Persecution, he moved to Rome, where he lived until his death after the year 309.