David Ryazanov (Russian: Дави́д Ряза́нов), born David Borisovich Goldendaj (March 10, 1870 – January 21, 1938), was a political revolutionary, Marxist theorist and archivist. Ryazanov is best remembered as the founder of the Marx-Engels Institute and editor of the first large-scale effort to publish the complete works of these two founders of the modern socialist movement. Ryazanov is also remembered as a prominent victim of the Great Terror of the late 1930s.