Giannozzo Manetti (1396–1459) was an Italian politician and diplomat from Florence, who was also a humanist scholar of the early Italian Renaissance.
Manetti was the son of a wealthy merchant. His public career began in 1429. He participated in municipal government as a member of the advisory council, as an ambassador, and in various gubernatorial positions in the city. Manetti was an eyewitness of the dedication of Santa Maria del Fiore on 25 March 1436, of which he left a record, the Oratio de Secularibus et Pontificalibus Pompis in Consecratione Basilicae Florentinae. His views on Florentine relations with Venice proved unpopular among the ruling class, and he put himself into voluntary exile, spending the last years of his life in Naples.
He was a Latinist and a translator of Greek; he also studied Hebrew so that he could read the Hebrew Bible and the rabbinic commentaries. These readings convinced him that the Bible needed translation anew from the early manuscripts. After his death, Manetti's sizable library found its way into the Biblioteca Vaticana.
As an author, Manetti's style was an imitation of Cicero. He is now remembered principally as the author of De dignitate et excellentia hominis libri IV ("On the Dignity and Excellence of Man in Four Books"), completed in manuscript in 1452 or 1453. It was a response to Pope Innocent III's De miseria humane conditionis. His Pistoiese History, composed in 1446–47, was the first contemporary critical response to Leonardo Bruni's innovative and monumental History of the Florentine People. He also wrote a commentary on Aristotle and biographies of Dante Alighieri, Giovanni Boccaccio, Pope Nicholas V, Francesco Petrarca, Seneca, and Socrates.
Manetti's circle of humanist intellectuals included Carlo Marsuppini, Poggio Bracciolini, Leonardo Bruni, Francesco Filelfo, Niccolò Niccoli, Palla Strozzi, and Lorenzo Valla.