Simón Radowitzky (Stepanice, Ukraine, 10 September or 10 November 1891 – Mexico City, Mexico, 29 February 1956) was a militant Ukrainian Argentine worker and anarchist. He was one of the best-known prisoners of the penal colony in Ushuaia, Tierra del Fuego, where he was held for the assassination of Ramón Lorenzo Falcón, a head of police responsible for the brutal repression of Red Week in 1909 in Buenos Aires.