Esther Frumkin (Yiddish: עסטער פרומקין; 1880 – 8 June 1943), born Malkhe Khaye Lifshitz and also known as Mariya Yakovlevna Frumkina, was a Belarusian Bundist revolutionary and publicist and Soviet politician who served as leader of the General Jewish Labour Bund in Lithuania, Poland and Russia, and later of the Yevsektsiya in the Soviet Union. An ardent proponent of the Yiddish language, her political position on Jewish assimilation satisfied neither traditional Jews nor the Soviet leaders.