Pope Anastasius III (died June 913) was Pope from April 911 to his death in 913. He was a Roman by birth. A Roman nobleman, Lucian, is sometimes recognized as his father, although other sources assert that he was the illegitimate son of his predecessor Pope Sergius III (904–911). Almost nothing is recorded of Pope Anastasius III, his pontificate falling in the period when Rome and the Papacy were in the power of Theophylact, Count of Tusculum, and his wife Theodora, who approved Anastasius III's candidacy. Under his reign the Normans of Rollo were evangelized.
His papacy faced renewed threats from the Saracens, after they established themselves on the Garigliano river.
He was buried in St. Peter's Basilica.