A rabbi (; Hebrew: רַבִּי, romanized: rabbī, IPA: [ʁəbːi]) is a spiritual leader or religious teacher in Judaism. A person becomes a rabbi by being ordained by another rabbi—known as semikhah—following a course of study of Jewish history and texts, including the Tanakh, Midrash, Mishnah, Tosefta, Talmud, Halakha, and rabbinic commentaries thereon. The basic form of the rabbi developed between the Second Temple (167 BCE–73 CE)—being heavily influenced by the Pharisees—and Rabbinic periods (70–640 CE), when learned teachers—overlapping with the Tannaim, Amoraim, Savoraim, and early Geonim—assembled to codify Judaism's written and oral laws. The title "rabbi" was first used in the first century CE. In more recent centuries, the duties of a rabbi became increasingly influenced by the duties of the Protestant Christian minister, hence the title "pulpit rabbis." Further, in 19th-century Germany and the United States, rabbinical activities such as delivering sermons, pastoral counseling, and representing the community to the outside all increased in importance.
Within the various Jewish denominations, there are different requirements for rabbinic ordination, and differences in opinion regarding who is recognized as a rabbi. Non-Orthodox movements, including Conservative Judaism, Reform Judaism, Reconstructionist Judaism, and Jewish Renewal, have set their requirements for semikhah based on what they consider halakhic reasons (as in Conservative Judaism) and ethical reasons (as in Reform and Reconstructionist) Judaism).