Chaim Ozer Grodzinski was a Av beis din, posek, and Talmudic scholar in Vilnius, Lithuania in the late 19th and early 20th centuries for over 55 years. He played an instrumental role in preserving Lithuanian yeshivas during the Communist era, and Polish and Russian yeshivas of Poland and during the Nazi invasion of Poland in 1939, when he arranged for these yeshivas to relocate to Lithuanian cities.