Pacian was a 4th-century Spanish prelate who served as the bishop of Barcelona from approximately 365 until his death in 391. A priest and writer, he is recognized as a Father of the Church due to his significant theological contributions. He was the father of Nummius Aemilianus Dexter, a high-ranking official under Theodosius I. His theological works addressed important subjects such as baptism, ecclesiastical discipline, and the primacy of the papacy, often in response to the Novatianist movement.