Yannai is both a given name and a surname. Notable people with the name include:
Alexander Yannai (–), more commonly latinized in English as Alexander Jannaeus, second king of the Hasmonean Dynasty Michal Yannai (born 1972), Israeli actress Rabbi Yannai (), also transliterated as Rabbi Jannai, Jewish sage Yannai (Payetan) (), Byzantine Galilee payyetan