Educated at Indraprastha College and St.Stephen's College, Delhi, she became a Professor of Constitutional History at Banaras Hindu University.
Like her contemporaries Aruna Asaf Ali and Usha Mehta, she came to the forefront during the Quit India Movement. She later worked closely with Mahatma Gandhi during the Partition riots. She accompanied him to Noakhali in 1946. She was one of the few women who were elected to the Constituent Assembly and was part of the subcommittee that drafted the Indian Constitution. She became a part of the subcommittee that was handed over the task of laying down the charter for the constitution of India. On 15 August 1947 she sang Vande Mataram in the Independence Session of the Constituent Assembly. After independence she remained involved with politics in Uttar Pradesh. She was elected to the Lok Sabha in 1952 and 1957 from New Delhi constituency and served as a Minister of State for Small Scale Industries. In 1962, she was elected to the Uttar Pradesh Vidhan Sabha from Kanpur and served in the Cabinet in 1962. In 1963, she became the Chief Minister of Uttar Pradesh, the first woman to hold that position in any Indian state. The highlight of her tenure was the firm handling of a state employees strike. The first-ever strike by the state employees which continued for 62 days took place during her regime. She relented only when the employees' leaders agreed for compromise. Although the wife of a socialist, Kriplani cemented her reputation as a firm administrator by refusing their demand for pay hike. In 1967, she was elected to the 4th Lok Sabha from Gonda constituency in Uttar Pradesh. She retired from politics in 1971 and remained in seclusion till her death in 1974.