Saint Nonnus was a 5th-century Christian bishop and monk originally from Egypt. According to hagiographical traditions, he moved to Syria, where he served as a bishop, potentially in Heliopolis or Edessa. He is most widely recognized for his role in the conversion of the famous courtesan Pelagia. By highlighting the contrast between her physical care and the spiritual neglect of the local assembly, he inspired her to repent, leading to her baptism and a life of asceticism.