Dawid Moryc Apfelbaum (some sources give Mieczysław or Mordechaj as his second name, and Appelbaum as his surname), nom de guerre "Kowal" ("Blacksmith") (?-4/28/1943) was allegedly an officer in the Polish Army and a commander of the Jewish Military Union (Żydowski Związek Wojskowy, ŻZW), during the Warsaw Ghetto Uprising. His very existence have been questioned by some historians, who argue that there is no credible evidence to suggest that there was a person by that name involved in the ŻZW in any capacity.