Rudolf Leonhard (27 October 1889, in Lissa, German Empire (today Leszno, Poland) – 19 December 1953, in East Berlin) was a German author and communist activist.
Leonhard came from a family of lawyers and studied law and Philology in Berlin and Göttingen. In 1914 he volunteered for the German military effort in World War I, but quickly converted to pacifism and was brought before a military court for his convictions.
In 1918 he joined the USPD (Independent German Social Democratic Party) and fought alongside Karl Liebknecht and Rosa Luxemburg in the 1918 revolution. In 1919, he joined the KPD (Communist Party of Germany), but left that party in favor of the left-communist KAPD (German Communist Workers’ Party), which he also left after a year. In 1918 he married the author Susanne Köhler, but was divorced from her after one year.
From 1919 onwards he was a freelance author for the publication Die Weltbühne, and worked for the publishing house Verlag Die Schmiede as a lector and as the editor of two series of books, “Außenseiter der Gesellschaft” (Outsiders of Society) and “Berichte aus der Wirklichkeit” (Reports from Reality). In late November 1925, he began and led the Gruppe 1925 which counted Bertolt Brecht, Alfred Döblin, Albert Ehrenstein, Leonhard Frank, Walter Hasenclever, Walter Mehring and Kurt Tucholsky among its members. After a difference of opinion, Leonhard left the group in 1927.