KATZ, REUVEN (1880–1963), talmudist. After studying in various yeshivot, Katz went to Vilna to study under Ḥayyim Ozer *Grodzinski. He became known as the Illui ("prodigy") of Olshany. He married the daughter of Abraham *Maskileison. After holding appointments in a number of towns, including Minsk in 1905, Indura in 1909, and Stawiski in 1923, he joined a delegation visiting the United States and remained there as rabbi of Bayonne, New Jersey. In 1932 he was appointed chief rabbi of Petaḥ Tikvah where he also headed the Lomza Yeshivah, founded by the heads of the Lithuanian yeshivah of the same name. Katz headed a variety of communal organizations, including the aid committee for Grodno Jewry and the Aguddat ha-Rabbanim of Poland. He was vice president of Aguddat ha-Rabbanim of America and in Israel he was president of Aguddat Rabbanei Yehudah ve-ha-Sharon and an associate of the Council of the Chief Rabbinate and of the Va'ad ha-Yeshivot. Among his published works are the responsa Degel Re'uven (3 pts., 1923–49); Duda'ei Re'uven (1928; 2nd ed. 2 pts., 1954) on the Pentateuch; and Sha'ar Re'uven (1952), a collection of essays on topical and practical problems. Of his sons, Aaron succeeded him as rosh yeshivah in Petaḥ Tikvah, Simeon served on the bet din there, Michael and Leon taught at Yeshiva *University, while a fifth son, Abraham *Katsh, became president of Dropsie University.
Harkavy, in: R. Katz, Sha'ar Re'uven (1952), 5–11 (introd.); Bergstein, in: Shanah be-Shanah (1965), 447–52; Raphael, in: Sinai, 56 (1965), 183f.; A. Shurin, Keshet Gibborim (1964), 141–6; Tidhar, 3 (1949), 1490f.