Astorre III Manfredi (20 June 1485 – 9 June 1502) was Lord of Faenza from 1488 to 1501.
In 1494, Astorre married Bianca Riario, the daughter of Caterina Sforza, and was loved by his subjects. In 1501, the Papal armies of Cesare Borgia conquered Faenza. The brave seventeen-year-old Astorre was subsequently invited to join them.
Although Astorre and Cesare got along well, Astorre posed a threat to the general, being the Lord of Faenza through his bloodline. As Cesare returned to Rome, he ordered Micheletto Corella to drown Astorre and his younger brother in the Tiber by tying rocks to their feet.