Alexander Lvovich Parvus (Russian: Алекса́ндр Льво́вич Па́рвус), born Israel Lazarevich Gelfand (September 8, 1867, Berazino – December 12, 1924, Berlin), was a Marxist theoretician, revolutionary, and a controversial activist in the Social Democratic Party of Germany. He also is said to have acted as a German intelligence agent.