Baron Otto Gustav von Wächter (8 July 1901, Vienna, Austria-Hungary – 14 July 1949, Rome, Italy) was an Austrian lawyer, Nazi politician and member of the SS, a paramilitary organisation of the Nazi Party with the rank, in 1944, of SS-Gruppenführer (Major General).
During the occupation of Poland in World War II, he was the Governor of the district of Kraków in the General Government and then of the District of Galicia (now for the most part in Ukraine). Later, in 1944, he was appointed as head of the German Military Administration in the puppet state of the Republic of Salò in Italy. During the last two months of the war he was responsible for the non-German forces at the Reich Main Security Office (RSHA) in Berlin.
In 1940 68,000 Jews were expelled from Kraków and in 1941 the Kraków Ghetto was created for the remaining 15,000 Jews by his decrees. On 28 September 1946 the Polish government requested the Military Governor of the United States Zone that Wächter be delivered to Poland for trial for "mass murder, shooting and executions. Under his command of District Galicia more than one hundred thousand Polish citizens lost their lives,...”
He managed to evade the Allied authorities for 4 years. In 1949, Wächter was given refuge by pro-Nazi Austrian bishop Alois Hudal in the Vatican where he died the same year, aged 48, allegedly from kidney disease although some sources claim he died of poisoning.
Otto Gustav von Wächter was the third child and only son of Martha (née Pfob), daughter of the owner of the Graben Hotel in Vienna Centre. His father, Joseph Freiherr von Wächter, was born in northern Bohemia and served in the Austro-Hungarian Army. In the last year of the First World War, Joseph Freiherr von Wächter was decorated with the Knight's Cross of the Order of Maria Theresia, which earned him the title of Freiherr (Baron).