Platina was born at Piadena (Platina in Latin), near Cremona.
He first enlisted as a private soldier, and was then appointed tutor to the sons of the Marquis Ludovico III Gonzaga, task previously held by Iacopo da San Cassiano and Ognibene da Lonigo. In 1457, he went to Florence, and studied under the Greek scholar Argyropulos. In 1462 he proceeded to Rome, probably in the suite of Cardinal Francesco Gonzaga. After Pius II had reorganized the College of Abbreviators (1463), and increased the number to seventy, Platina, in May 1464, was elected a member.
De honesta voluptate et valetudine
Probably in the summer of 1465 Platina composed De honesta voluptate et valetudine ("On honourable pleasure and health"). This first printed cookbook, a monument of medieval cuisine in Renaissance intellectual trappings, left the press in 1474 and ran into dozens of editions, disseminating Roman ideas about fine dining throughout Western Europe. In a display of humanist learning Platina embedded recipes from the famous chef, Maestro Martino de' Rossi, whom he had met in the summer of 1463 at Albano, where Platina was the guest of Martino's employer, a cardinal. The cookbook also happens to contain the oldest recorded usage of cannabis in cooking.
When Paul II abolished the ordinances of Pius, Platina with the other new members was deprived of his office. Angered by this, he wrote a pamphlet insolently demanding from the pope the recall of his restrictions. When called upon to justify himself he answered with insolence and was imprisoned in the Castel Sant'Angelo, being released after four months on condition that he remain at Rome. In February 1468, with about twenty other humanists, he was again imprisoned on suspicion of heresy and of conspiring against the life of the pope. The latter charge was dropped for lack of evidence, while they were acquitted on the former. However, members of the Roman Academy were found guilty of immorality.
After his release on July 7, 1469, he expected to be again in the employ of Paul II, who, however, declined his services. Platina threatened vengeance and executed his threat, when at the suggestion of Sixtus IV he wrote his Vitæ Pontificum Platinæ historici liber de vita Christi ac omnium pontificum qui hactenus ducenti fuere et XX (1479). In it he paints his enemy as cruel, and an archenemy of science. For centuries it influenced historical opinions until critical research proved otherwise. In other places party spirit is evident, especially when he treats of the condition of the Church. Notwithstanding, his Lives of the Popes is a work of no small merit, for it is the first systematic handbook of papal history. Platina felt the need of critical research, but shirked the examination of details. By the end of 1474 or the beginning of 1475 Platina offered his manuscript to Pope Sixtus IV; it is still preserved in the Vatican Library. The pope's acceptance may cause surprise, but it is probable he was ignorant of its contents except insofar as it concerned his own pontificate up to November, 1474. After the death of Giovanni Andrea Bussi, Bishop of Aleria, the pope appointed Platina librarian with a yearly salary of 120 ducats and an official residence in the Vatican. He also instructed him to make a collection of the chief privileges of the Roman Church. This collection, whose value is acknowledged by all the annalists, is still preserved in the Vatican archives. In the preface Platina not only avoids any antagonism towards the Church but even refers with approbation to the punishing of heretics and schismatics by the popes, which is the best proof that Sixtus IV, by his marks of favour, had won Platina for the interests of the Church. Besides his principal work Platina wrote several others of smaller importance, notably: Historia inclita urbis Mantuæ et serenissimæ familiæ Gonzagæ. The Pinacoteca Vaticana contains a famous fresco by Melozzo da Forlì representing Sixtus IV Appointing Platina as Prefect of the Vatican Library.