Rabbi Meir Margolis (Margaliot), born around 5467 (1707), was one of the first rabbis of the Chassidic movement and a disciple of the Baal Shem Tov. He was the son of Rabbi Tzvi Hirsch Margolis, rabbi of Jazłowiec. His elder brother, Rabbi Yitzchak Dov, himself a disciple of the Baal Shem Tov, drew him to Chassidism, and the two brothers became attached to the Baal Shem Tov in their youth.

His first wife was the daughter of Rabbi Chaim of Horodenka. He later married Reizel, daughter of his uncle Rabbi Aryeh Leib Auerbach, av beit din of Stanislav and author of Nachalat Aryeh, and raised her son from her first marriage, Rabbi Meshulam Zalman Ashkenazi, later rabbi of Lublin, as his own.

He served as a dayan in Brody, as rabbi and av beit din of Horodenka, then as rabbi of Jazłowiec, before becoming av beit din in Lemberg (Lviv). In 5514 (1754) he was elected rabbi of Lemberg and its entire district. In 1775 a decree of the Polish king Stanisław Poniatowski appointed him rabbi of Braslav and all of Polish Ukraine, and in July 1777 (5537) he became rabbi and av beit din of Ostroh and its region. His prestige helped the Chassidic movement grow. Several of his sons became rabbis, among them Rabbi Shaul in Lublin and Rabbi Betzalel, who succeeded him in Ostroh.

A major halachic authority, he is known by the title of his work Meir Netivim, in two parts: responsa and Torah novellae (Polonnoye, 5551). Works: Or Olam on the 613 commandments, Derech HaTov VeHaYashar on the four sections of the Shulchan Aruch, and Sod Yachin UVoaz, a work of Chassidic Kabbalah.

He passed away in Ostroh on 10 Iyar 5550 (April 24, 1790) and was buried in the town's cemetery, near the Maharsha.