Chaim Zhitlowsky (Yiddish: ??? ???????????; Russian: ???? ???????? ??????????) (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; later, a founding member and theoretician of the Socialist Revolutionary Party in Russia; and an ideologist of Yiddishism and Jewish Diaspora nationalism, which influenced the Jewish territorialist and nationalist movements.
He was an advocate of Yiddish language and 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."