Pierre de Thury[1] (died 9 December 1410) was a French bishop and cardinal of the Avignon Obedience, who served as a royal secretary and Master of Requests, and then as papal Nuncio and Apostolic Legate on several occasions.

Their uncle Guillaume, the brother of Girard de Thury, had been Archbishop of Lyon from 1358 to 1365, and had founded a chapel in the parish of Cuisery in Bresse châlonnaise.

He was recommended to Pope Gregory XI by Duke Jean of Berri (Bourges) in 1377, with a view to the Archbishopric of Vienne, but the post had already gone elsewhere.

The Diary of Bishop Jean le Fevre of Chartres indicates that, on his return from Toulouse, Pierre spent the next three years continuously at the Curia in Avignon.

The French leaders then tried to persuade the cardinals in a private meeting to adopt the view which had been arrived at the royal Court.

When the embassy had returned to Paris, a number of courtiers at Avignon began to work on the cardinals to retract their agreements.

Cardinal de Thury acted as their spokesman in accusing Benedict of being a promoter of heresy, a perjurer, and a person of dissolute morals.

[20] He presided at the marriage of the Comte de Clermont, son of Louis the Duke of Bourbon, and the Comtesse d'Eu on 24 June 1400 in the royal palace in Paris.

Cardinal Thury and Patriarch Simon de Cramaud were opposed to the reconciliation, but finally went to the King and submitted.

[22] In the Spring of 1407, Pierre de Thury was one of several cardinals appointed by Benedict XIII to deal with an embassy from Gregory XII, which had come to France to attempt to agree upon a place where the two popes could meet and resolve the schism.

On 7 November 1409 Cardinal de Thury left the Curia in Prato, sent by Pope Alexander V to be Legate in Avignon and Papal Vicar, the first to hold that office.