Jean Mabillon (November 23, 1632-December 27, 1707) was a Benedictine monk and scholar, considered the founder of palaeography and diplomatics.

He was born in Saint-Pierremont in Champagne, France, the son of Estienne Mabillon (who died in 1692 at age 104) and Jeanne Guérin. At age 12 he entered the Collège des Bons Enfants in Reims and in 1650 entered the seminary. He left the seminary in 1653 and instead became a monk in the Maurist abbey of St. Remi . His devotion to his studies there left him ill, and he was sent to Corbie in 1658 to regain his strength. In 1663 he transferred again, to Saint Denis Basilica in Paris, and the next year to the abbey of Saint-Germain-des-Prés in Paris, where he met and worked with many other scholars, including Charles du Fresne, sieur du Cange, Etienne Baluze, and Louis-Sébastien Le Nain de Tillemont.

In Saint-Germain, Mabillon edited the works of St. Bernard (published in 1667), and also worked on the Lives of the Benedictine Saints (published in 1668). In 1681 he published De re diplomatica libri sex, which investigated the different types of medieval scripts and manuscripts and is now seen as the foundation work of palaeography and diplomatics. The work brought him to the attention of Jean-Baptiste Colbert, who offered him a pension (which he declined), and King Louis XIV. He began to travel throughout Europe, to Flanders, Switzerland, Germany, and Italy, in search of medieval manuscripts and books for the royal library.

However, there were opponents to his work. Some of the less scholarly monks in his own abbey criticized his Lives for being too academic, and the abbot of La Trappe declared that he was breaking the rules of his order by devoting his life to study rather than manual labour. He also caused trouble by denouncing the veneration of the relics of "unknown saints," wrote a controversial critique of the works of St. Augustine, and was accused of Jansenism, but at all times he was supported by the king and the church.

In 1701 Mabillon was appointed by the king as one of the founding members of the Académie des Inscriptions et Belles-Lettres, and in 1704 a supplement to De re diplomatica was published. In 1707 he died and was buried in the church of Saint-Germain-des-Prés , in Paris.