Giovanni Boccamazza (died 1309) was an Italian Cardinal. He was from the Roman nobility, related to the Savelli family and was a nephew of Pope Honorius IV. He was made bishop of Monreale, near Palermo, in 1278, and was there at the time of the Sicilian Vespers (1282). After fleeing Sicily. , he was made cardinal-bishop of Frascati on 22 December in 1285, by Honorius IV. He was then sent as a papal legate to northern Europe. He attended the significant synod of March 1287 in Würzburg, considered as a German national council.