Stanisiław Kasznica (July 25, 1908 - May 12, 1948) was the last commander of Narodowe Sily Zbrojne (NSZ - National Armed Forces), the armed right wing guerilla and political organisation in Poland during the WWII and in the period following it. The organisation was accused by the Polish Communistic Soviet-backed regime of chauvinism and anti-Semitism.

He was born in Lwów, and his father, Stanisław, was rector and professor of the Poznan University.

He was arrested by the Polish Secret Police in 1947 by and condemned by the court marshall to death. He was executed on May 12 1948 in Warsaw.

Kasznica used numerous pseudonyms including Stanisław Wąsacz, Wąsowski, Przepona, Służa, Maszkowski, and Borowski.