Rattan Bai (15 July 18901 January 1986) was an Indian actress and singer. She was the mother of actress Shobhna Samarth, grandmother of actresses Nutan and Tanuja, great-grandmother of actors Kajol, Tanishaa Mukerji and Mohnish Bahl.
Rattan Bai Kalwant was a singer who wrote bhajans, composed and sang them as well. She published the lyrics of her bhajans to distribute among friends who would sing with her during Maha Shivaratri celebrations at her home in Chembur. Rattanbai acted in only one Marathi film called Swarajyachya Seemewar, as Chatrapati Shivaji Maharaj's mother.