Guido de' Medici (...– Rome, 13~23 June 1537) was an Italian Catholic archbishop. Son of Antonio di Giuliano de' Medici, of the branch of the Marquises of Castellina, and of Selvaggia di Felice del Beccuto, he began an ecclesiastical career, obtaining numerous benefices: he was prior of Sant'Apollinare , provost of Ognissanti in Florence, parish priest of Sant'Ippolito in Castelfiorentino and, in 1506, he replaced his deceased brother Averardo as canon of the Cathedral of Santa Maria del Fiore; He renounced his canonry in 1532. The pontificates of his relatives Leo X (1513-1521) and Clement VII (1523-1534) represented for him the opportunity to be admitted to the papal court: he was familiar, protonotary apostolic and secret chamberlain of Pope Leo and domestic prelate of Pope Clement, who appointed him castellan of Castel Sant'Angelo and ambassador to Alessandro de' Medici. He was elected bishop of Venosa in 1527 and then metropolitan archbishop of Chieti on 2 January 1528: he never resided in this city due to his duties at the Roman Curia and sent, as his suffragan, the bishop of Lavello.