François Guillaume de Castelnau de Clermont-Ludève (1480-1541) was a French diplomat and Cardinal
He was administrator of Saint-Pons-de-Thomières (1502, 1511-14 and 1534-39); archbishop of Narbonne from 1502; bishop of Auch in 1507; bishop of Senez, 1508-9; bishop of Valence 1523-1531, and bishop of Agde from 1531. He was created Cardinal by Pope Julius II in 1503. Legate in Avignon 1513-1541. He participated in the Papal conclave, 1523. Pope Clement VII named him bishop of Frascati in December 1523. Several sources indicate that he was Dean of the College of Cardinals in the ponificate of Pope Paul III.