Kantor Lev Osipovich (real name Yehuda-Leib) (1849, Vilna – 1915, Riga) — publicist, writer, rabbi, and community activist.

Born into the family of the cantor of the Great Vilna Synagogue, Lev Kantor received a traditional Jewish religious education. By the age of 17, he was already regarded as a skilled Talmudist. He entered the Vilna Rabbinical School and in 1873 graduated from the Zhitomir Rabbinical Seminary. He then continued his studies in Berlin, earning a doctorate in medicine. At the same time, he worked as a correspondent for Golos Moskvy (Voice of Moscow) and as editor of the Hebrew newspaper Ha-Tzfirah.

In 1879, Lev Kantor settled in St Petersburg, where he became editor of the journal Russkii evrei (The Russian Jew), contributing journalistic essays and feuilletons under the pseudonym Ben Bag-Bag. He also published under his own name and as Ben-Yosef in Evreiskaia biblioteka (The Jewish Library) and Voskhod (The Dawn), where he wrote surveys of Jewish literature and critical essays.

Lev Kantor founded and edited the first daily Hebrew-language newspaper, Ha-Yom (1886–87). In 1887, he began writing in Yiddish — editorials, literary-historical essays, political commentaries, and feuilletons — for Yidishes Folksblat, later becoming its editor. He was also a contributor to Der Fraynd, the first daily Jewish newspaper in Yiddish, as well as other Russian-Jewish periodicals.

He was among the creators of the feuilleton genre in the Jewish press and was instrumental in introducing Semyon Frug and Zalman Frishman to Jewish literature. He also contributed articles to the Russian-language Jewish Encyclopedia.

From 1890 to 1904, Lev Kantor served as rabbi in Libau (Liepāja), later in Vilna, and from 1911 in Riga.