R. Joseph Leib Bloch (1860–1930) was a Lithuanian yeshivah head. He showed exceptional ability from childhood and at the age of 14 he traveled to Chelm where he studied under R. Eliezer Gordon. He continued his studies with R. Naphtali Zevi Judah Berlin at Volozhin. After his marriage to the daughter of R. Gordon, he moved to Telz, where he assisted his father-in-law, who had been appointed rabbi and rosh yeshivah. In 1902, after resigning from the yeshivah in protest against the resistance of a number of the students to the study of musar, he was appointed rabbi of Varna, a small village near Telz. He served later as rabbi of Shadova, where he established his own yeshivah. In 1910 R. Bloch was appointed rabbi of Telz and rosh yeshivah, succeeding his father-in-law. Under his leadership, the yeshivah attracted large numbers of students. In addition to his lectures on halakhah, R. Bloch also gave talks on musar. He took the unusual step of founding a teachers' seminary, which produced hundreds of educators, and a preparatory school, in which secular studies were taught. Thanks to these auxiliary institutions, the yeshivah of Telz occupied a central position, with an enrollment, at times, of as many as 500 students. Active in communal affairs, Bloch served as a member of the executive of the Association of Lithuanian Rabbis and as one of the leaders of Agudat Israel. Prominent among his sons were R. Abraham Isaac, who succeeded his father in Telz, and R. Elijah Meir, who was one of the yeshivah principals. His other sons and sons-in-law also taught in Telz. R. Bloch's ethical essays were published in Shi'urei Da'at (pt. 1, 1949; pt. 2, 1953; pt. 3, 1956). His halakhic lectures appeared in Shi'ur Halakhah (pt. 1, 1932; pt. 2, 1943; pt. 3, 1958).