Guido Ascanio Sforza di Santa Fiora (26 November 1518, Rome — 6 October 1564, Mantua) was an Italian cardinal, known also as The cardinal of Santa Fiora. Son of Costanza Farnese and therefore grandson of Pope Paul III, brother of Cardinal Alessandro Sforza (1565), uncle of Cardinal Francesco Sforza and great-uncle of Cardinal Federico Sforza (1645). During his time as a cardinal he served as legate as well as administrator of different towns and episcopal sees.