Baal Shem (Hebrew pronunciation: [ˈbaʕal ʃɛm], Hebrew: בַּעַל שֵׁם, pl. Baalei Shem) in Hebrew meaning "Master of the Name", refers to a historical Jewish occupation of certain kabbalistic rabbis with knowledge of using names of God in Judaism for practical kabbalah healing, miracles, exorcism and blessing.
The unofficial title was given by others who recognised or benefited from the Baal Shem's ability to perform wondrous deeds, and emerged in the Middle Ages, continuing until the early modern era. Baal Shem were seen as miracle workers who could bring about cures and healing, as well having mystical powers to foresee or interpret events and personalities. They were considered to have a "direct line" to Heaven, evoking God's mercies and compassion on suffering human beings. In Jewish society, the practical theurgic role of Baalei Shem among the common folk was a mystical institution, contrasted with the more theosophical and ecstatic Kabbalistic study circles, which were isolated from the populace. The Baal Shem, the communal Maggid preacher and the Mokhiakh ((מוֹכִיחַ/preacher) of penitence were seen as lower level unofficial Jewish intelligentsia, below contract Rabbis and study Kabbalists.
The activity of Baalei Shem among the community, as well as the influence of kabbalistic ideas, contributed to the popular belief in Tzadikim Nistarim (Concealed Righteous). Hasidic tradition records Elijah Ba'al Shem of Chelm in the 16th century, founding a "Nistarim" mystical brotherhood to offer physical and spiritual encouragement to the Jewish populace, making him the first Baal Shem, and from which movement Hasidism later emerged.