Joseph Sáenz de Aguirre, OSB (24 March 1630 – 19 August 1699) was a Cardinal, and learned Spanish Benedictine.

He directed the studies in the Monastery of St. Vincent of Salamanca for fifteen years, and became its abbot.

His work against the Declaration of the Gallican Clergy of 1682 won him a cardinal's hat and the warm eulogy of Innocent XI.

He was buried in the Spanish Church of St. James in Rome, and his heart was deposited in Monte Cassino, as he had requested.

His more important works are on philosophical and theological subjects, but he also produced writings on ecclesiastical history, commentaries on the theology of St. Anselm, two volumes of miscellanea, and a book to prove that the De Imitatione Christi was by the Benedictine, Jean Gerson.