The Fareynikte Partizaner Organizatsye (Yiddish: פֿאַראײניקטע פּאַרטיזאַנער אָרגאַניזאַציע; "United Partisan Organization"; referred to as FPO by its Yiddish initials) was a Jewish resistance organization based in the Vilna Ghetto that organized armed resistance against the Nazis during World War II. The clandestine organisation was established by Zionist as well as Communist partisans. Their leaders were writer Abba Kovner and Yitzhak Wittenberg.