Musa Bigiev (sometimes known as Luther of Islam) (1870/75 in Novocherkassk, Russian Empire – 28 October 1949 in Cairo, Egypt) was a Tatar philosopher, theologian, publicist and one of the leaders of the Jadid movement.
After receiving his education in Kazan, Bukhara, Istanbul and Cairo, he became a political activist for the Ittifaq, the political organisation of the Muslims of Russia.
He also taught in Orenburg, wrote journalistic texts and translated classic works into Tatar.
After emigrating from the Soviet Union, he travelled Europe and the Middle and Far East while writing and publishing.