Raphael Abramovitch Rein (1880–1963), best known as Raphael Abramovitch, was a Russian socialist, a member of the General Jewish Workers' Union in Lithuania, Poland and Russia (Bund), and a leader of the Menshevik wing of the Russian Social-Democratic Workers' Party (RSDRP).
Abramovitch emigrated from Soviet Russia in 1920, landing in Berlin, where he was a co-founder of the long-running Menshevik journal Sotsialisticheskii vestnik (The Socialist Courier).
After 1940, with the rise of fascism in Europe, he made his way to the United States, where he lived his final years.