Rabbi Re'em Ha'Cohen (born in March 10, 1957 Seventh of Adar (B) H'Tshi"z; in Hebrew: רא"ם הכהן) is an Israeli Rabbi and one of the Rabbis of the Religious Zionism. Ha'Cohen is the Rosh yeshiva of Yeshivat Otniel (Together with Rabbi Binyamin Kalmanzon) and the Rabbi of the Israeli settlement, Otniel.
Ha'Cohen grew up in Jerusalem's Sha'arei Hesed neighborhood near Rav Shlomo Zalman Auerbach and visited his home frequently. Ha'Cohen claims to be deeply influenced by Auerbach. Rav Re'em studied under Rav Arieh Binah at Netiv Meir Yeshiva high school and at Yeshivat Har Etzion, under Rabbi Aharon Lichtenstein. Ha'Cohen received rabbinical ordination from Lichtenstein and from Rabbi Eliezer Waldenberg (the Tzitz Eliezer). Ha'Cohen was a Ra"m at Shevut Yisrael Yeshiva of Efrat and in Rav Haim Druckman's yeshiva, Or Etzion. In 1993, he joined Harav Beni Kalmanson to found and head Yeshivat Otniel. Since 1998, he has also served as Otniel's community rabbi.
According to Rav Re'em, the learning in the beit midrash must be connected to the outside world, as the inner parts of the Torah must be connected to the outer parts. For this reason, his teaching references many different sources ranging from academic and professional, to halachic and kabalistic sources.
Ha'Cohen thinks that it is legally binding to donate ones organs and have an organ donor card. He forbids smoking as a form of suicide. He requires his followers to wear techelet.