Jivatram (also spelled Jiwatram) Bhagwandas Kripalani was born in Hyderabad in Sindh in 1888. Following his education at Fergusson College in Pune, he worked as a schoolteacher before joining the freedom movement in the wake of Gandhi's return from South Africa. From 1912 to 1917 Kripalani worked as a lecturer of English and history in Griers Bhumihar Brahmin College,(now L.S.College)Muzaffarpur, Bihar. Kripalani was involved in the Non-Cooperation Movement of the early 1920s. He worked in Gandhi's ashrams in Gujarat and Maharashtra on tasks of social reform and education, and later left for Bihar and the United Provinces in northern India to teach and organise new ashrams. He courted arrest on numerous occasions during the Civil Disobedience movements and smaller occasions of organising protests and publishing seditious material against the British raj.

He grew close to Gandhi and at one point, he was one of Gandhi's most ardent disciples. Kripalani was a familiar figure to generations of dissenters, from the Non-Cooperation Movements of the 1920s to the Emergency of the 1970s.

Kripalani joined the All India Congress Committee, and became its general secretary in 1928–29.

Acharya Kripalani was born on the same day as Maulana Azad, who also was prominent freedom fighter. Kripalani succeeded the latter as the President of Indian National Congress at the Meerut session in 1946.

Nehru, however, supported Kripalani in the election of the Congress President in 1950. Kripalani, supported by Nehru, was defeated by Patel's candidate Purushottam Das Tandon. Bruised by his defeat, and disillusioned by what he viewed as the abandonment of the Gandhian ideal of a countless village republics, Kripalani left the Congress and became one of the founders of the Kisan Mazdoor Praja Party. This party subsequently merged with the Socialist Party of India to form the Praja Socialist Party.

For a while it was even believed that Nehru, stung by the defeat, was considering abandoning the Congress as well; his several offers of resignation at the time were all, however, shouted down. A great many of the more progressive elements of the party left in the months following the election. Congress's subsequent bias to the right was only balanced when Nehru obtained the resignation of Tandon in the run up to the general elections of 1951.

Kripalani remained in opposition for the rest of his life and was elected to the Lok Sabha in 1952, 1957, 1963 and 1967 as a member of Praja Socialist Party. His wife since 1938, Sucheta Kripalani, remained in Congress and went from strength to strength in the Congress Party, with several Central ministries; she was also the first female Chief Minister, in Uttar Pradesh.

In October 1961, Kripalani contested the Lok Sabha seat of V.K. Krishna Menon, then serving as Minister of Defence, in a race that would come to attract extraordinary amounts of attention. The Sunday Standard observed of it that "no political campaign in India has ever been so bitter or so remarkable for the nuances it produced". Kripalani, who had previously endorsed Menon's foreign policy, devoted himself to attacking his vituperative opponent's personality, but ultimately lost the race, with Menon winning in a landslide.

Kripalani moved the first-ever No confidence motion on the floor of the Lok Sabha in August 1963, immediately after the disastrous India-China War.

While remaining active in electoral politics, Kripalani gradually became more of a spiritual leader of the socialists than anything else; in particular, he was generally considered to be, along with Vinoba Bhave, the leader of what remained of the Gandhian faction. He was active, along with Bhave, in preservation and conservation activities throughout the 1970s.

In 1972-3, he agitated against the increasingly authoritarian rule of Nehru's daughter Indira Gandhi, then Prime Minister of India. Kripalani and Jayaprakash Narayan felt that Gandhi's rule had become dictatorial and anti-democratic. Her conviction on charges of using government machinery for her election campaign galvanised her political opposition and public disenchantment against her policies. Along with Narayan and Lohia, Kripalani toured the country urging non-violent protest and civil disobedience. When the Emergency was declared as a result of the vocal dissent he helped stir up, the octogenarian Kripalani was among the first of the Opposition Leaders to be arrested on the night of 26 June 1975. He lived long enough to survive the Emergency and see the first non-Congress government since Independence following the Janata Party victory in the 1977 polls.

In the 1982 film Gandhi by Richard Attenborough, J.B. Kripalani was played by Indian actor Anang Desai.

A stamp was issued on 11 November 1989 by the Indian Postal Department to commemorate the 101st anniversary of his birth.

His autobiography My Times was released 22 years after his death by Rupa publishers in 2004. In the book, he accused his fellow members of Congress (except Ram Manohar Lohia, Mahatma Gandhi and Khan Abdul Gaffar Khan) of "moral cowardice" for accepting or submitting to plan to partition India.

In spite of being ideologically at odds with both the right-wing Vallabhbhai Patel and the left-wing Jawaharlal Nehru – he was elected Congress President for the crucial years around Indian independence in 1947. After Gandhi's assassination in January 1948, Nehru rejected his demand that the party's views should be sought in all decisions. Nehru, with the support of Patel, told Kripalani that while the party was entitled to lay down the broad principles and guidelines, it could not be granted a say in the government's day-to-day affairs. This precedent became central to the relationship between government and ruling party in subsequent decades.