Giulia Farnese (Italian pronunciation: [ˈdʒuːlja farˈneːze, -eːse]; 1474 – 23 March 1524) was an Italian noblewoman, a mistress to Pope Alexander VI, and the sister of Pope Paul III. Known as Giulia la Bella (Italian for 'Julia the Beautiful'), she was a member of the noble Farnese family, who were prominent leaders in the Italian regions of Parma and Piacenza. After marrying into the noble Orsini family in the Papal States, Farnese soon acquainted herself with, and initiated an affair with, the Spanish Cardinal Rodrigo de Borja. When the cardinal was elected Pope, Farnese continued the increasingly advantageous liaison, which enabled her to have her brother Alessandro made a cardinal, until losing Alexander's favor at the turn of the century.
Farnese spent most of her later years governing the castle of Carbognano, previously a property which Alexander had given to her husband. She died in 1524 in Rome at the residence belonging to Alessandro, who would later be elected Pope Paul III.