Jacob Katz (Hebrew: ???? ?"?) (born 15 November 1904 in Magyargencs, Hungary, died 20 May 1998 in Israel) was a Jewish historian and educator.
He established the history curriculum used in Israel's High Schools.
Katz described "traditional society" and deployed sociological methods in his study of Jewish communities, with special attention to changes in halakhah (Jewish law) and Orthodoxy.
He pioneered the modern study of Orthodoxy and its formation in reaction to Reform Judaism.