Banai (Marathi: बाणाई Bāṇāi, sometimes बानाई), also known as Banu (Bāṇu, बानू) and Banu-bai (Bāṇu-bāī, बानू-बाई), is a Hindu goddess and the second wife of Khandoba, a form of the god Shiva worshipped in the Deccan – predominantly in the Indian states of Maharashtra and Karnataka. Khandoba is portrayed as a king of Jejuri, where his chief temple stands. Some traditions do not give her the status of a legal wife and treat her as a concubine of Khandoba.
While scriptures related to Khandoba do not mention Banai, she is a central subject of folk songs. Banai is considered as a Dhangar, a sheep herding caste, and is sometimes regarded to be of celestial origin. Oral traditions chiefly discuss the tale of her marriage to Khandoba and her conflicts with his first wife Mhalsa. Banai is an antithesis of Mhalsa; together they complete the god. Banai is generally depicted with Khandoba and often is also accompanied by Mhalsa.
Banai does not enjoy independent worship, but is worshipped as Khandoba's consort in most of his temples. She is the patron goddess of the Dhangar community and is worshipped as a protector of their herds.
Though Khandoba is a god with five wives, his first two consorts Mhalsa and Banai are the most important. The tale of the King or god with two wives is retold with some variation across India: Murugan and his wives Devasena and Valli; Venkateswara, Lakshmi and Padmavati being some examples. The motif of Shiva and his wives Parvati and Ganga is told in the Puranas.