Hermann of Salza (c. 1179 - March 20, 1239) was the fourth Grand Master of the Teutonic Knights from 1209 to 1239 and an important politician of his age.

He was possibly born around 1179, to a ministerial family from Thuringia. The precise time of his entry into the Order is unknown, but he first appears in 1209 as Grand Master. As such he may have spent some time in the Mediterranean Sea region during the first year of his rule. During this period the activities of the Knights were extended from Spain to Livonia.

He was a friend and councillor of Holy Roman Emperor Frederick II, for whom from 1222 onwards he represented as a mediator in the Papal curia. Pope Honorius III also recognized Hermann's capabilities, and granted the Teutonic order an equal status with the Knights Hospitaller and the Knights Templar, after it had gone into decline under previous Grand Masters.

In 1211 he led an expedition against the Cumans at the request of Andrew II of Hungary, but the Hungarian nobles complained of the order's presence and they were forced to leave by 1225. Meanwhile, Hermann accompanied Frederick on the Fifth Crusade against Damietta in 1219, and he was decorated for bravery by John of Brienne, the titular King of Jerusalem. Hermann later convinced Frederick to undertake the Sixth Crusade, and was partially responsible for Frederick's marriage to Yolanda, John of Brienne's daughter.

Upon his return to Europe he helped to lift Frederick's excommunication. He was then requested by Conrad of Masovia to fight the pagan Prussians. In 1230 the knights began their lengthy campaign to Christianize the Prussians of the Baltic area.

Hermann's subsequent visits with the Pope or the emperor brought new privileges and donations to the order. He was also able to obtain the incorporation of the Livonian Brothers of the Sword into the Teutonic order in 1237. The importance of Hermann's role as mediator between Pope Gregory IX and the emperor can be seen by the fact that all communication between Frederick and the pope broke off with Hermann's death.

Within the Teutonic order, however, the knights began to grow dissatisfied at the absence of their Grand Master, so they recalled him and had him withdraw from his political life. However, he was less successful as a religious leader, and soon retired to Salerno in 1238. He died there March 20, 1239.