Pierre Gassendi was born – as Pierre Gassend, son of the peasant farmer Anthoine Gassend and his wife Françoise Fabry – on January 22, 1592, in the village of Champtercier, near Digne in Provence. This was the year of Montaigne's death. He attended the Collège de Digne from 1599 to 1607 – where he learned, primarily, Latin – and the Faculté d'Aix beginning in 1609, studying philosophy with Père Philibert Fesaye. He also followed a course of theology that included Greek and Hebrew. Fesaye was a Carmelite, and the ratio studiorum of the Carmelites refers to Aquinas, Toletus, Averroes, and the Carmelite doctor John Bacon or Baconthorp. Baconthorp attacked intelligible species; denied the univocity of being; held that universals precede the action of the intellect and that external objects are intelligible per se although understanding them requires an agent intellect; equated essence with quiddity; and maintained a formal distinction between essence and existence. Gassendi adopted none of these doctrines, save the rejection of intelligible species.

Gassendi was recognized as an exceptional student from early on, and received his doctorate in theology in 1614, at the age of 24, at which time he took the four minor orders of the church and became the theological canon of Digne Cathedral. He kept this job until he was promoted to provost in 1634, after some legal wrangling. In 1616, Gassendi was ordained to the priesthood.