Chaim Ozer Grodzinski was a prominent rabbi and halachic authority in the early 20th century. Born in 1863 in Ostrów Mazowiecka, Poland, he became known for his deep knowledge of Jewish law and his ability to address complex legal questions. He served as the rabbi of Vilna, a significant center of Jewish learning, and was influential in the Yeshiva movement. Grodzinski authored several important works, including Achiezer, which is a comprehensive collection of responsa. His contributions to Jewish scholarship and law have had a lasting impact, and he is remembered as a key figure in the development of modern Orthodox Judaism.