Eleonore Baur (7 September 1885 – 18 May 1981), also known as Sister Pia, was a senior NSDAP figure and the only woman to have participated in the Munich Beer Hall Putsch.
Born Eleonore Mayr in Bad Aibling, Bavaria, Baur's mother died when Baur was an infant, and when she was five Baur moved to Munich with her father and stepmother. In Munich Baur left school aged 14 to work as a midwife's assistant. At 15 she gave birth to an illegitimate child whose fate is currently unknown. At 19 she gave birth to a second illegitimate son named Willhelm, whom she gave up for adoption, then soon after she moved to Egypt to work as a nurse's assistant at a Cairo hospital.
Baur returned to Munich in 1907, calling herself "Sister Pia", and worked for the Roman Catholic charitable order Gelbes Kreuz. In 1908 or 1909 she married Ludwig Baur, a mechanical engineer. The marriage ended in divorce after five or six years. Baur served as a nurse during World War I and then assisted the Freikorps Oberland troops during their battle against the Bavarian Soviet Republic and in the Baltic campaign in 1919. In 1923 she married for the second time, a hotel manager named Sponseil ten years her junior. This marriage also ended in divorce.
In 1920, Baur met Adolf Hitler on a tram in Munich and helped found the National Socialist German Workers' Party (Nationalsozialistische Deutsche Arbeiterpartei (NSDAP)). Baur became one of the most visible Nazi figures in Munich in the spring of 1920, and was arrested on 11 March 1920 for disturbing the peace following an anti-Semitic speech at a women's rally in Munich. Her subsequent acquittal made her a hero of the Nazi movement.
Baur continued to be active in German politics, giving speeches and organising Nazi-based charitable events, and on 9 November 1923 was the only woman to participate in the Beer Hall Putsch, during which she received minor injuries and for which she later received the Blood Order, being one of only two German and 14 Austrian women to be awarded the party's highest decoration. Throughout the rise of the Nazis and following their assumption of power in 1933, Baur remained close to the Nazi leadership, accompanying Hitler on picnic trips, and Heinrich Himmler appointed her welfare sister for the Waffen-SS at Dachau Concentration Camp in 1933.