Fra' Didier de Saint-Jaille (died 26 September 1536) was the 46th Grand Master of the Order of Saint John between 1535 and 1536.

De Saint-Jaille was a French nobleman who joined the Knights Hospitaller as part of the Langue of France.

He was particularly known for his great prudence, and was elected as Grandmaster following Piero de Ponte's death.

Coincidentally, both Didier de Saint-Jaille and Hompesch are buried in Montpellier.

While he was away from Malta, the knight Jacques Pelliquen acted as Lieutenant Grandmaster, and during his rule Maltese and Calabrian soldiers destroyed El Haid Tower which was close to Tripoli (then a possession of the Order).