Rani Sada Kaur (Punjabi: ਸਦਾ ਕੌਰ; c. 1762 – 1832) was chief of the Kanhaiya Misl from 1789 to 1821. She was the wife of Gurbaksh Singh Kanhaiya, the heir of Jai Singh Kanheya, the leader of the Kanhaiya Misl and is sometimes referred to as Sardarni Sada Kaur. After her husband's death in 1785 and her father-in-law's death in 1789, she became the chief of the Kanhaiya Misl. An intelligent and ambitious woman, she was also the mother-in-law of Maharaja Ranjit Singh (the founder of the Sikh Empire) and played an important role in his rise to power in Punjab.