Shmuel Schneersohn (or Rabbi Shmuel of Lubavitch or The Rebbe Maharash) (17 March 1834 – 14 September 1882 OS) was an Orthodox rabbi and the fourth Rebbe (spiritual leader) of the Chabad Lubavitch chasidic movement.
Schneersohn was born in Lyubavichi, on 2 Iyar 1834, the seventh son of the Tzemach Tzedek. He faced competition from three of his brothers, primarily from Rabbi Yehuda Leib Schneersohn who established a dynasty in Kapust upon their father's death. Other brothers also established dynasties in Lyady, Nizhyn, and Ovruch.
In 1848 Schneersohn was married to the daughter of his brother, Rabbi Chaim Shneur Zalman Schneersohn. After several months she died, and he then married the Rebbetzin Rivkah, a granddaughter of Rabbi Dovber Schneuri, the Mitteler Rebbe. He had three sons, Rabbi Zalmman Aharon, Rabbi Sholom Dovber and Rabbi Menachem Mendel as well as one daughter, Devorah Leah.
Schneersohn was said to have had chariots on call for the evacuation of books in time of fire.