Roger de Moulins was Grand Master of the Knights Hospitaller from 1177 to his death in 1187.

The Hospitallers were rivals of the Knights Templar, but Pope Alexander III persuaded Roger to make a truce with them in 1179. In 1184 he toured Europe with Arnold de Toroga, the Grand Master of the Templars, and Heraclius, the Latin Patriarch of Jerusalem, and established the Hospitaller order in England, France and Germany. On his way back he helped the Normans attack Thessalonica in 1185.

During his time as Grand Master the Hospitallers became more involved in the politics of the Kingdom of Jerusalem. Roger opposed Raynald of Chatillon and Guy of Lusignan, and at first refused to hand over his key to the royal treasury when Guy was crowned in 1186. He took part in the raid against Saladin at Cresson near Nazareth on May 1, 1187, where he may have been killed; however, he may have survived to fight at the Battle of Hattin on July 4. If he survived Cresson, he was certainly captured and executed at Hattin by Saladin, who considered the Hospitallers and Templars his deadliest enemies.

Roger was succeeded by William Borrel, who served as custodian of the Hospitallers for a brief time in 1187, and then by Hermangard d'Asp, who served as custodian until 1190. A new Grand Master was not chosen until Garnier de Naplous was elected in 1190 during the Third Crusade.