Pedro Téllez-Girón, 3rd Duke of Osuna (17 December 1574 – 24 September 1624) was a Spanish nobleman and politician. He was the 2nd Marquis of Peñafiel, 7th Count of Ureña, Spanish Viceroy of Sicily (1611–1616), Viceroy of Naples (1616–1620), a Knight of the Order of the Golden Fleece since 1608, Grandee of Spain, member of the Spanish Supreme Council of War, and the subject of several poems by his friend, counselor and assistant, Francisco de Quevedo.
He served as a footsoldier and climbed the ranks, an unusual career for an aristocrat, during the Eighty Years' War. As Viceroy of Sicily and Naples, Osuna reorganized the local administration and armadas with new strategies and ships, and implemented a highly profitable and successful privateering system against the Ottoman Empire, the Republic of Venice and the Barbary pirates. Despite opposition in the court, he maintained Mediterranean dominance during the ten years of his mandates, achieving victories like Cape Corvo, Cape Celidonia and Ragusa. At his peak, his individual naval power is believed to have rivaled that of the Sultan of the Ottoman Empire.