Ignace Reiss (1899–1937)–AKA "Ignace Poretsky," "Ignatz Reiss," "Ludwig," "Ludwik", "Hans Eberhardt," "Steff Brandt," Nathan Poreckij, and "Walter Scott (an officer of the U.S. military intelligence)"–was one of the "Great Illegals" or Soviet spies who worked in third party countries where they were not nationals in the late 1920s and 1930s.