Simon Wiesenthal, KBE, was an Austrian-Jewish architectural engineer and Holocaust survivor who became famous after World War II for his work as a Nazi hunter who pursued Nazi war criminals in an effort to bring them to justice.

Following four and a half years in the German concentration camps such as Janowska, Plaszow, and Mauthausen during World War II, Wiesenthal dedicated most of his life to tracking down and gathering information on fugitive Nazis so that they could be brought to justice for war crimes and crimes against humanity. In 1947, he co-founded the Jewish Historical Documentation Center in Linz, Austria, in order to gather information for future war crime trials. Later he opened Jewish Documentation Center in Vienna. Wiesenthal wrote The Sunflower, which describes a life-changing event he experienced when he was in the camp.

A biography by Guy Walters asserts that many of Wiesenthal's claims regarding his education, wartime experiences and Nazi hunting exploits are false or exaggerated. Walters calls Wiesenthal’s claims "an illusion mounted for a good cause". It is difficult to establish a reliable narrative of Wiesenthal’s life due to the inconsistencies between his three memoirs which are in turn all contradicted by contemporary records. It is partly thanks to Wiesenthal that the Holocaust has been remembered and properly documented.

Wiesenthal died in his sleep at age 96 in Vienna on September 20, 2005, and was buried in the city of Herzliya in Israel on 23 September. He is survived by his daughter, Paulinka Kriesberg, and three grandchildren. The Simon Wiesenthal Center, located in Los Angeles in the United States, is named in his honor.