Sigmund Sobolewski () (May 11, 1923 – August 7, 2017) was a Polish activist, lecturer and Holocaust survivor. He was the 88th prisoner to enter Auschwitz on the very first transport to the concentration camp on June 14, 1940. He remained a prisoner for four and a half years during World War II. He was a critic of Holocaust denial and was known for having confronted modern neo-Nazis, anti-Semites and Holocaust deniers.