Isaac Leib Peretz (, ) (May 18, 1852 – April 3, 1915), also sometimes written Yitskhok Leybush Peretz was a Yiddish language author and playwright from Poland. Payson R. Stevens, Charles M. Levine, and Sol Steinmetz count him with Mendele Mokher Seforim and Sholem Aleichem as one of the three great classical Yiddish writers. Sol Liptzin wrote: "Yitzkhok Leibush Peretz was the great awakener of Yiddish-speaking Jewry and Sholom Aleichem its comforter... Peretz aroused in his readers the will for self-emancipation, the will for resistance against the many humiliations to which they were being subjected."