Francisco Casimiro Pimentel de Quiñones y Benavides (4 March 1655 in Madrid – 15 January 1709 Madrid), IX Duke of Benavente, XIII count of Mayorga, XI count of Luna, V marquis of Jabalquinto, VI marquis of Villa Real de Purullena, was a Spanish aristocrat who served the Spanish Royal House.
He was the son of Antonio Alonso Pimentel y Herrera Zúñiga, VIII Duke of Benavente, and Isabel Francisca de Benavides, III Marquess of Jabalquinto.
In 1689, was one of the witnesses of the testament of Queen Marie Louise d'Orléans, and shortly after he was sent by Carlos II to Ferrol to accompany the King's new wife, Maria Anna of Neuburg, to Valladolid for the ratification of the marriage.
During the last years of Carlos II's reign, Benavente was one of the courtiers closest to the monarch, very much against Queen Maria Anna de Neuburg's wishes.
A supporter of Philip V of Spain in the War of Spanish Succession, Benavente was confirmed by the new monarch as Sumiller de Corps.