Rabbi Yosef Peimer, known as Rabbi Yossel Slutsker (of Slutsk), was born around 5556 (1796) in Skuodas (Shkud), Lithuania, to Rabbi Meir and Glika Peimer. In his youth he studied as a chavruta of Yaakov Benditman, who later became rabbi of Bauska.

He studied at the Volozhin yeshiva and became the leading disciple of Rabbi Chaim of Volozhin, who gave him semichah and personally trained him for the rabbinate. His contemporaries regarded him as a “third mouth” of the Vilna Gaon. After his marriage to Reizel, daughter of Rabbi Meir, he was appointed rabbi of Lukniki, where Rabbi Yisrael Salanter apparently studied under him.

In the winter of 5589 (1828-1829), still a young man, he was elected rabbi of Slutsk, a post he held for thirty-five years. He sent responsa throughout Lithuania and was counted among the greatest rabbis of his generation. In 5621 (1861) he accepted an appointment as rabbi of Minsk but withdrew at the pleading of the Slutsk community. In 5618 (1858) he sat on the rabbinical court that set the arrangements for running the Volozhin yeshiva after the long dispute that had divided it, alongside Rabbi David Tevel of Minsk, Rabbi Yitzchak Elchanan Spektor and Rabbi Ze'ev Wolf Landau, the Maggid Meisharim of Vilna.

He was known for his firmness in public affairs and his gentleness toward the poor and the young. He discouraged teachers from using corporal punishment and was noted for his modesty. Most of his writings were lost in a fire at his son's house on the eve of Rosh Chodesh Av 5680 (1920). Two volumes of his responsa survived and were published in Jerusalem in the 1980s as Shu"t Rabbeinu Yosef MiSlutsk; his Derashot uBiurim on the Torah have also been printed.

He wrote his will on 29 Nissan 5624 and passed away the next day, 30 Nissan 5624 (May 6, 1864). Rabbi Yosef Dov HaLevi Soloveitchik, the Beit HaLevi, succeeded him a few months later.