John Sieg (February 3, 1903 – October 15, 1942) was a railroad worker and journalist who publicized Nazi atrocities through the underground Communist press and fought against National Socialism in the German Resistance. He was a key member of the Red Orchestra.
John Sieg was born in Detroit, Michigan, the son of a mechanic. After the death of his father in 1912, he lived with his grandfather in Germany and became a German citizen in 1920.
In the beginning of the 1920s, Sieg went to school to become a teacher, but when his grandfather died in 1923, he had to quit. He returned to the Detroit and met his future wife, Sophie, in 1924, while working as a college intern. He stayed in the United States until February 1928, when Sieg and his wife returned to Germany and he became a freelance author in Berlin.
He began writing articles for Die Tat, a newspaper published by Adam Kuckhoff. After joining the Communist Party of Germany that same year, he began to write for the arts section of the KPD newspaper, Die Rote Fahne and he got to know Wilhelm Guddorf and Martin Weise.
He was arrested by the Sturmabteilung (storm troopers) in March 1933 and held till June. Upon his release, he began working with the Communist Resistance in the Berlin suburb of Neukölln, becoming the focal point of several groups. He had close contact with Arvid Harnack and Kuckhoff. He took part in leafletting campaigns and shared political information. In 1937, he got a job with the Deutsche Reichsbahn, eventually working as a signaller at the S-Bahn station at Papestraße. As a railroad employee, Sieg was able to make use of work-related travel and free travel to build connections with other Resistance groups, such as the one organized around Bernhard Bästlein.