Semikhah (Hebrew: סמיכה) is the traditional Jewish name for rabbinic ordination.

The original semikhah was the formal "transmission of authority" from Moses through the generations. This form of semikhah ceased between 360 and 425 CE. Since then semikhah has continued in a less formal way. Throughout history there have been several attempts to reestablish the classical semikhah.

In recent times, some institutions grant ordination for the role of hazzan (cantor), extending the "investiture" granted there from the 1950s. Less commonly, since the 1990s, ordination is granted for the role of lay leader – sometimes titled darshan. Ordination may then also be specifically termed סמיכה לרבנות ('rabbinical ordination'), סמיכה לחזנות ('cantorial ordination'), or הסמכת מגיד ('maggidic ordination').

The title of "rabbi" has "proliferated greatly over the last century". Nowadays semikha is also granted for a limited form of ordination, focused on the application of Halakha in specific settings as opposed to underlying Talmudic knowledge. Outside Orthodox Judaism, in fact, the curriculum may emphasize "the other functions of a modern rabbi such as preaching, counselling, and pastoral work".