Stella Kübler-Isaacksohn née Goldschlag (10 July 1922 – 1994), was a German Jewish woman who collaborated with the Gestapo during World War II, exposing and denouncing Berlin's underground Jews.
She was born Stella Goldschlag and raised in Berlin as the only child in a middle-class, assimilated Jewish family. After the 1933 seizure of power by the Nazis, she, like other Jewish children, was forbidden to go to a public school, so she attended the Goldschmidt School, set up by the local Jewish community. At school, she was known for her beauty and vivacity.
The family fell on hard times when Jews were purged from positions of influence and her father lost his job with the newsreel company Gaumont. Her parents attempted to leave Germany after Kristallnacht in 1938 to escape the Nazi regime, but were unable to get visas for other countries. Stella completed her education in 1938, training as a fashion designer at the School of Applied Art in Nurnbergerstrasse.
In 1941, she married a Jewish musician, Manfred Kübler. They had met when both were working as Jewish forced-labourers in a war plant in Berlin. In about 1942, when the large deportation programme of Berlin Jews into extermination camps began, she disappeared underground, using forged papers to pass as a non-Jew — owing to her blonde-haired, blue-eyed 'Aryan' appearance.
In the spring of 1943, she and her parents were arrested by the Nazis. Stella Kübler was subjected to torture. In order to avoid deportation of herself and her parents, she agreed to become a "catcher" (German: Greiferin) for the Gestapo, hunting down Jews hiding as non-Jews (referred to as "U-Boats"). She was promised a salary of 300 Reichsmark for each Jew that she betrayed. She proceeded to comb Berlin for such Jews and, as she was familiar with a large number of Jewish people from her years at her segregated Jewish school, Kübler was very successful at finding her former schoolmates and handing their information over to the Gestapo, while posing as a U-Boat herself. Some of Kübler's efforts to apprehend Jews in hiding included promising them food and accommodation, meanwhile turning them over to the Nazi authorities; she also followed clues provided to her by the Gestapo. The data concerning the number of her victims varies, depending on different sources of information, from between 600 and 3,000 Jews. Stella Kübler's charisma and striking good looks were a great advantage in her pursuit of underground Jews. The Nazis called her "blonde poison". She is mentioned in The Forger, Cioma Schonhaus' 2004 account of living as an underground Jew in Berlin, and also Berlin at War (Roger Moorhouse, 2010).