Avraham Mordechai Alter (Polish: Abraham Mordekhaj Alter, Hebrew: אברהם מרדכי אלתר‎; 25 December 1865 – 3 June 1948), also known as the Imrei Emes after the works he authored, was the fourth Rebbe of the Hasidic dynasty of Ger, a position he held from 1905 until his death in 1948. He was one of the founders of the Agudas Israel in Poland and was influential in establishing a network of Jewish schools there. It is claimed that at one stage he led over 200,000 Hasidim.