Ranuccio Farnese (September 17, 1630 — December 11, 1694), or Ranuccio II, was the sixth Duke of Parma and Piacenza from 1646 until his death nearly 50 years later. He was the eldest son of Odoardo Farnese, fifth Duke of Parma, and Margherita de Medici. His son, Odoardo II Farnese , become the seventh Duke of Parma upon Ranuccio II's death.

Ranuccio II witnessed the continued decline of the duchy during his rule (a decline which had started during the rule of his father), losing the Castro territories in a series of events initiated by his father and known as the Wars of Castro. In 1649, Pope Innocent X accused Ranuccio II of murdering Cardinal Cristoforo Giarda, who was on his way to the city of Castro at the time of his death. In retaliation, forces loyal to the Pope occupied and razed the city; it was never rebuilt.

References

• http://www.comune.piacenza.it/english/history/Ifarnese.htm (Retrieved January 23, 2005)
• http://www.italycyberguide.com/History/factspersons/wxyz.htm (Retrieved January 23, 2005)
• http://page.freett.com/mako_vl/name/hausf.html (Retrieved January 23, 2005)