Chaim Zhitlowsky (Yiddish: חײם זשיטלאָװסקי; Russian: Хаим Осипович Житловский) (April 19, 1865 – May 6, 1943) was a Jewish socialist, philosopher, social and political thinker, writer and literary critic born in Ushachy, Vitebsk Governorate, Russian Empire (present-day Usachy Raion, Vitebsk Region, Belarus).
He was a founding member of the Union of Russian Socialist Revolutionaries;[1] a founding member and theoretician of the Socialist Revolutionary Party in Russia,[2] and a key promoter of Yiddishism and Jewish Diaspora nationalism, which influenced the Jewish territorialist and nationalist movements. He was an advocate of Yiddish language, culture and was a vice-president of the Czernowitz Yiddish Language Conference of 1908, which declared Yiddish to be "a national language of the Jewish people."[3]