Alexander Altmann (April 16, 1906 – June 6, 1987) was an Orthodox Jewish scholar and rabbi born in Kassa, Austria-Hungary (present-day Košice, Slovakia). He emigrated to England in 1938 and later settled in the United States, working productively for a decade and a half as a professor within the Philosophy Department at Brandeis University. He is best known for his studies of the thought of Moses Mendelssohn, and was indeed the leading Mendelssohn scholar since the time of Mendelssohn himself. He also made important contributions to the study of Jewish mysticism, and for a large part of his career he was the only scholar in the United States working on this subject in a purely academic setting. Among the many Brandeis students whose work he supervised in this area were Elliot Wolfson, Arthur Green, Heidi Ravven, Lawrence Fine, and Daniel Matt.
Alexander Altmann was the son of the Chief Rabbi of Trier, one of the oldest Jewish communities in Germany. Altmann received his Ph.D. in philosophy from the University of Berlin in 1931, writing his dissertation on the philosophy of Max Scheler, and was ordained rabbi by the Hildesheimer Rabbinical Seminary of Berlin in the same year. From 1931 to 1938 he served as rabbi in Berlin and professor of Jewish philosophy at the Seminary. After fleeing Nazi Germany in 1938, Altmann served as communal rabbi in Manchester, England from 1938 to 1959. There, in addition to his responsibilities as a community leader, he continued to independently pursue his scholarly studies, publishing in 1946 a translation and commentary of Saadia's Beliefs and Opinions. His scholarly activities ultimately led him to found and direct the Institute of Jewish Studies from 1953 to 1958, which at the time was an independent institution. He there edited the Journal of Jewish Studies and Scripta Judaica and authored his work on Isaac Israeli. While Altmann was at Manchester, Bert Trautmann, a former soldier for Nazi Germany and prisoner of war, was being considered as a player for Manchester City Football Club, which had many Jewish fans; Altmann approved, despite the Nazis having killed his parents and other family members. Altmann's intervention may have been decisive for the unprecedented acceptance of a former P.O.W. into the team. Trautmann went on to become a very successful goalkeeper.