Yitzhak Isaac Halevy (Rabinowitz) (September 21, 1847 – May 15, 1914) (Hebrew: ???? ?????? ????) was a rabbi, Jewish historian, and founder of the Agudath Israel organization.
Relatively little of his correspondence survived the Holocaust, and so information concerning his activities is scarce.
A somewhat hagiographical treatment based on discovered correspondence of Isaac Halevy is to be found in Reichel (1969), and this forms the basis for the present article.