Yitzchak Zelig Morgenstern of Kotzk-Sokolov (Hebrew: יצחק זליג מורגנשטרן, מסוקולוב, Yiddish: זעליג מארגענשטערן, מסאקאלאוו, of Sokolov; 1866 – 16 October 1939 (3 Cheshvan 5700)) was an Admor and Rosh yeshiva, a member of the Moetzes Gedolei HaTorah and a leader of Polish Jewry before the Holocaust, who died shortly after the war began.
