Tiberio Crispo (31 January 1498 – 10 October 1566), the son of Giovanni Battista Crispo and Silvia Ruffini, who, after her husband's death, was the mistress of Alessandro Farnese. It was believed that Tiberio was an illegitimate son of Farnese, who became Pope Paul III. He was certainly a natural brother of Costanza Farnese (born ca. 1500) and Ranuccio Farnese (died 1529), the two undisputed legitimate children of Paul III, were born before his election as pope in 1534.