R. Judah Loen Landau (Leo; 1866–1942), South African rabbi, scholar, poet, and playwright. Landau was born in Zatozce, Galicia. His father Moses Issachar Landau was a maskil and regular contributor to the Hebrew press. Landau attended the German gymnasium at Brody (Galicia), yeshivot, and the Jewish Theological Seminary and University of Vienna and soon came under the influence of Hebrew writers, poets, and dramatists, such as P. Smolenskin, N. I. Fischmann, and R. A. Broides. As a student in Vienna, Landau used to write theater and opera reviews of Jewish interest for Ha-Maggid. Early in his life Landau supported the movement for national revival by word and deed, became an ardent supporter of Theodor Herzl, and attended several of the early Zionist congresses. When on a visit to London in 1900 for the Fourth Zionist Congress, M. Gaster persuaded him to stay. He was minister of the North Manchester Hebrew Congregation until 1904, when he went to Johannesburg as rabbi of the Johannesburg Hebrew Congregation.

In 1915 Landau became chief rabbi of the United Hebrew Congregation of Johannesburg and of the Federation of Synagogues of the Witwatersrand; he was also appointed professor of Hebrew at Witwatersrand University. In nearly four decades of spiritual leadership in the South African Jewish community, Landau participated in and stimulated a great variety of activities and organizations: religious, charitable, cultural, and Zionist.

Landau's contributions to modern Hebrew literature were mainly in drama and poetry. His poems and articles first appeared in a number of Hebrew periodicals, where he used the pseudonym of Hillel ben Shahar. Over fifty of his works were published.