Julius Stieglitz (May 26, 1867 – January 10, 1937) was an American chemist of German Jewish origin. He was a teacher and organic chemist with a major interest in pharmaceutical and medicinal chemistry. He is known for the Stieglitz rearrangement, a rearrangement reaction in organic chemistry which commonly involves the formation of imines from hydroxylamines through a carbon to nitrogen shift, comparable to the key step of a Beckmann rearrangement. He died in Chicago on January 10, 1937.