Giovanni Doria (24 March 1573, Genoa – Palermo, Sicily, 19 October 1642), called Giannettino, the son of Giovanni Andrea Doria, 6th Prince of Melfi, and Princess Zenobia Doria del Carretto, 5th Princess of Melfi.
Doria studied philosophy and theology in Spain being promoted to the Cardinalate at the instance of King Felipe II of Spain. Once king Philip II died, he was created cardinal deacon, aged 31, in the consistory of June 9, 1604. Doria was granted permission to receive the sacred orders outside the Ember days, December 9, 1604. He participated in the first conclave of 1605, which elected Pope Leo XI, and in the second conclave of 1605, which elected Pope Paul V.
Doria received the red hat, the deaconry of S. Adriano, December 5, 1605, and Abbot commendatario of San Fruttuoso in Camogli. He was elected titular archbishop of Tessalonica and named coadjutor, with right of succession, of Palermo, on February 4, 1608 and was consecrated, May 4, 1608, at Rome, by Pope Paul V.
He succeeded to the see of Palermo, Sicily, July 5, 1608. Viceroy of Sicily and lieutenant of the king of Spain, February 8, 1610 - March 1611, July to August 1616, from August 1, 1624 to 1626 and from 1639 to June 1641.
Doria participated in the conclave of 1621, which elected Pope Gregory XV and participated in the conclave of 1623, which elected Pope Urban VIII. He opted for the order of cardinal priests and the title of San Pietro in Montorio, October 2, 1623. He celebrated the discovery of the relics of Saint Rosalia, and promoted her cult as patroness and protector of Palermo.
He died November 19, 1642, at Palermo and was buried in the chapel of S. Rosalia, in the metropolitan cathedral of Palermo.