Pedro Pacheco de Villena (29 June 1488, La Puebla de Montalban, near Toledo - 5 March 1560, Rome) also known as Pedro Pacheco Ladrón de Guevara, was a Spanish cardinal and viceroy of Naples. In Italian his name is spelled Pietro Pacecco. His nephew Francisco Pacheco de Toledo was also a cardinal.
Pedro Pacheco de Villena was the son of Alfonso Tellez Giron, son of Martin Vazquez de Acuña and Maria Teresa Giron, heiress of her House. His uncle was Marques de Villena. He studied at Salamanca. He was a chamberlain of Pope Alexander VI and followed him to Rome in 1522. He worked in several offices for the Roman Curia, notably as referendary at the Supreme Tribunal of the Apostolic Signatura. He was Dean of Santiago Cathedral and Archdeacon of Valpuesta. Charles V made him visitor to the chancellery of Valladolid and of Grenada.
He was appointed bishop of Mondoñedo (Mindionensis) in Galicia and was confirmed by Pope Paul III (Farnese) on September 6, 1532, and was later translated to the diocese of Ciudad Rodrigo, with the consent of Pope Paul given in Consistory on April 11, 1537.
He was named Bishop of Pamplona by the Emperor, an appointment confirmed by Pope Paul III in consistory on May 21, 1539. Pacheco took possession of his diocese by proxy of Dr. Martinez y Gaspar Lizano on July 10, 1539. He finally appeared personally to be enthroned on March 14, 1540. He carried out a visitation of the Cathedral Chapter of Pamplona. After a year of opposition and obfuscation, an agreement between the bishop and Canons was reached on April 14, 1541, for the enforcement of the regulation of the Canons. In August 1544, the Bishop convoked a Synod for his diocese, the thirteenth in the diocese's history. He established the custom of holding annual processions on Corpus Christi and its Octave, Easter day, the Feast of S. Augustine and the Feast of S. Francis. At the conclusion of the Synod, the Emperor summoned Pacheco to service at Court. .