Pietro Parenzo was a 12th-century Roman nobleman who served as the podestà of Orvieto. Appointed by Pope Innocent III to restore civil order during a period of intense religious and political division, he implemented a strict administration to stabilize the city. His efforts to maintain authority led to his assassination in May 1199 by members of the Cathar movement. Following his death, he was recognized as a martyr and a wonderworker, eventually becoming the patron saint of Orvieto.