Klausenburg /ˈkloʊzənbɜːrɡ/, also known as Sanz-Klausenburg, is a Hasidic dynasty that originated in the Transylvanian city of Cluj-Napoca (formerly Klausenburg), Romania.
At the behest of Rabbi Yekusiel Yehudah Halberstam, Klausenburger Rebbe from 1927–1994, the movement was split into two separate movements after his death, headed by his two sons. The Sanz-Klausenburger Hasidim are located in Borough Park, New York City, while the Sanzer Hasidim are based in Kiryat Sanz, Netanya, Israel. There are also modest followings in Jerusalem, Stamford Hill, Antwerp and Union City, New Jersey.
The Klausenburger Rebbes are descended from Rabbi Chaim Halberstam of Sanz, who was a disciple of Rabbi Naftoli Tzvi of Ropshitz. Rabbi Naftoli was a disciple of Rebbe Elimelech of Lizhensk author of Noam Elimelech. Rebbe Elimelech was a disciple of Rebbe Dovber, the Maggid (Preacher) of Mezritch, the primary disciple of the Baal Shem Tov, the founder of Hasidism.