Konrad Heiden (7 August 1901 – 18 June 1966) was an influential journalist and historian of the Weimar Republic and Nazi eras, most noted for his biographies of German dictator Adolf Hitler. Often, he wrote under the pseudonym "Klaus Bredow."
Heiden was born in Munich, Germany, on 7 August 1901, and graduated from the University of Munich in 1923. His father was a union organizer, his mother had a Jewish background. At the university, he organized a republican and democratic student body and became a member of the Social Democratic Party.
Heiden worked for the Frankfurter Zeitung and Vossischen Zeitung, but became a freelancer in 1932. A year later, he went into exile; first to Switzerland, then to France. He had seen the rise of the Nazi Party from upclose, first attending a party's meeting in 1920.
Heiden died in New York City, in the United States on 18 June 1966, having resided in the US for 26 years after fleeing from Germany.