Jacob ben Moses Bachrach (born in Seiny, in the governorate of Suwalki, which is now in Poland, May 9, 1824; died in Bialystok December 29, 1896) was a noted apologist of Rabbinic Judaism. He was descended from Rabbi Yair Chayim Bacharach, and in turn from the Maharal of Prague.
He received his earliest instruction from his grandfather, Judah Bachrach. For years he was superintendent of a Hebrew printing-establishment in Königsberg, where he edited, among other works, the Ṭurim of Jacob ben Asher, and added notes to the same. Later on he became manager of a distillery in Sevastopol, where he had the opportunity to develop into an assiduous student of Karaitic literature, and where he engaged in controversies with the representatives of the local Karaitic community. His works are chiefly devoted to a defense of rabbinical tradition against Karaism. In 1882 he went to Palestine in the interest of colonization.