Lotte Johanna Radtke was a guard at two concentration camps in the last period of World War II.

Lotte Johanna Radtke was born as Lotte Johanna Ostermann in Hamburg, Germany on August 8, 1923. She worked several jobs before she became a concentration camp guard in 1944. Her first post was at the Neuengamme concentration camp near her hometown. The young woman soon became known as one of the worst guards there. In the summer of 1944, Lotte was posted at th Helmstedt-Beendorf III subcamp near Ludwigslust, Germany. There she oversaw over 2,000 women prisoners who worked on constructing parts for German war planes. The inmates there feared her for her abuse and temper, and nicknamed her "Die Deutsche" (The German). In late March 1945 the British Army came close to the Helmstedt camp so the SS evacuated the surviving women. Lotte fled along with other guards and went back to her hometown of Hamburg, where she lived quietly. She later married and became Lotte Johanna Radtke. She was never prosecuted for her role in the deaths of thousands of women at the two camps.