Levi ben Gershon (1288–1344), better known by his Graecized name as Gersonides, or by his Latinized name Magister Leo Hebraeus, or in Hebrew by the abbreviation of first letters as RaLBaG, was a medieval French Jewish philosopher, Talmudist, mathematician, physician and astronomer/astrologer.
He was born at Bagnols in Languedoc, France.
According to Abraham Zacuto and others, he was the son of Gerson ben Solomon Catalan.