Fabio Biondi was born in Montalto in 1533 into an “ancient and civil family,” closely connected by kinship and friendship to the Peretti family, which gave birth to Pope Sixtus V and the influential Cardinal Alessandro Peretti. These family ties were the foundation of his ecclesiastical career.

After an initial experience as parish priest of the Church of S. Maria ad Collem in Montalto, when Felice Peretti was elected pope, he called Biondi to Rome, appointing him as tutor to his nephew Alessandro, whom he later elevated to the cardinalate. In 1588, in recognition of his services, Biondi was granted the title of Patriarch of Jerusalem. It is likely that the same pope also granted Biondi substantial benefices in Piedmont, including an abbey with an annual income of 1,000 scudi and a provostship in Vercelli. On October 1, 1592, Pope Clement VIII appointed him collector in Portugal. From August 1593, he also took on the role of vice-legate, significantly increasing the importance of his duties. While still serving in Lisbon, he made a highly successful visit to his patriarchal see in Jerusalem, receiving an exceptionally warm welcome from the Turkish authorities by order of the Sultan himself.

Biondi returned to Rome, where in 1602 Pope Clement VIII appointed him majordomo and prefect of the papal palace, positions he held until his death. Among his responsibilities was maintaining relations with the Christians of Congo, and his dedication earned him numerous papal privileges and concessions.

He died in Rome in 1618.