Ralph Austin Bard was a Chicago financier who served as Assistant Secretary of the Navy, 1941–1944, and as Under Secretary, 1944–1945. He is noted for a memorandum he wrote to Secretary of War Henry L. Stimson in 1945 urging that Japan be given a warning before the use of the atomic bomb on a strategic city. He was "the only person known to have formally dissented from the use of the atomic bomb without advance warning."