Simon Wiesenthal (31 December 1908 – 20 September 2005) was a Jewish Austrian Holocaust survivor, Nazi hunter, and writer. He studied architecture and was living in Lwów at the outbreak of World War II. He survived the Janowska concentration camp (late 1941 to September 1944), the Kraków-Płaszów concentration camp (September to October 1944), the Gross-Rosen concentration camp, a death march to Chemnitz, Buchenwald, and the Mauthausen concentration camp (February to 5 May 1945).

After the war, Wiesenthal dedicated his life to tracking down and gathering information on fugitive Nazi war criminals so that they could be brought to trial. In 1947, he co-founded the Jewish Historical Documentation Centre in Linz, Austria, where he and others gathered information for future war crime trials and aided refugees in their search for lost relatives. He opened the Documentation Centre of the Association of Jewish Victims of the Nazi Regime in Vienna in 1961 and continued to try to locate missing Nazi war criminals. He played a small role in locating Adolf Eichmann, who was captured by the Mossad in Buenos Aires in 1960, and worked closely with the Austrian justice ministry to prepare a dossier on Franz Stangl, who was sentenced to life imprisonment in 1971.

In the 1970s and 1980s, Wiesenthal was involved in two high-profile events involving Austrian politicians. Shortly after Bruno Kreisky, a Jew himself, was inaugurated as Austrian chancellor in April 1970, Wiesenthal pointed out to the press that four of his new cabinet appointees had been members of the Nazi Party. Kreisky, angry, called Wiesenthal a "Jewish fascist", likened his organisation to the Mafia, and accused him of collaborating with the Nazis. Wiesenthal successfully sued for libel, the suit ending in 1989. In 1986, Wiesenthal was involved in the case of Kurt Waldheim, whose service in the Wehrmacht and probable knowledge of the Holocaust were revealed in the lead-up to the 1986 Austrian presidential elections. Wiesenthal, embarrassed that he had previously cleared Waldheim of any wrongdoing, suffered negative publicity as a result of this event.

With a reputation as a storyteller, Wiesenthal was the author of several memoirs containing tales that are only loosely based on actual events. In particular, he exaggerated his role in the capture of Eichmann in 1960. Wiesenthal died in his sleep at age 96 in Vienna on 20 September 2005 and was buried in the city of Herzliya in Israel. The Simon Wiesenthal Center, headquartered in Los Angeles, is named in his honour.