Jayprakash Narayan was born on 11 October 1902 in the village of Sitabdiara (It was in Chapra district of Bihar when JP was born. At present it is in Ballia district of Uttar Pradesh, India). Sitabdiara is a large village, straddling two states and three districts—Chhapra and Arrah in Bihar and Ballia in Uttar Pradesh. His house was near the banks of the flood-prone Ghagra river in Lala Tola, Bihar. Every time the river swelled, the house would get a little bit damaged, eventually forcing the family to move a few kilometres away to a settlement which is now known as Jay Prakash Nagar and falls in Uttar Pradesh. He came from a kayastha family. He was the fourth child of Harsu Dayal and Phul Rani Devi. His father Harsu Dayal was junior official in the Canal Department of the State government and was often touring the region. When Narayan was 9 years old, he left his village to enroll in 7th class of the collegiate school at Patna. This was his first break from village life. JP stayed at a student hostel—Saraswati Bhawan—in which most of the boys were a bit older. Among them were some of Bihar's Future Leaders including its first chief minister, Krishna Singh , his deputy Anugrah Narayan Sinha and several others who were to widely become known in politics and academic world.

In Wisconsin, Jayaprakash was introduced to Karl Marx's Das Kapital. News of the success of the Russian revolution of 1917 made Jayaprakash conclude that Marxism was the way to alleviate the suffering of the masses. He delved into books by Indian intellectual and Communist theoretician M. N. Roy. His paper on sociology, "Social Variation", was declared the best of the year.

At the age of 18, Jayaprakash was married to Prabhavati Devi, daughter of Lawyer and nationalist Brij Kishore Prasad in October 1920. Prabhavati was very independent and on Gandhi's invitation, went to stay at his ashram while Jayaprakash continued his studies. Prabhavati Devi died in 1973 after a long battle with cancer.

After exhausting the courses at the Vidyapeeth, Jayaprakash decided to continue studies in the United States. At age 20, Jayaprakash sailed aboard the cargo ship Janus while Prabhavati remained at Sabarmati. Jayaprakash reached California on 8 October 1922 and was admitted to Berkeley in January 1923. To pay for his education, Jayaprakash picked grapes, set them out to dry, packed fruits at a canning factory, washed dishes, worked as a mechanic at a garage and at a slaughter house, sold lotions and taught. All these jobs gave Jayaprakash an insight into the difficulties of the working class. Jayaprakash was forced to transfer to The University of Iowa when fees at Berkeley were doubled. He was forced to transfer to many universities thereafter. He pursued his favourite subject, sociology, and received much help from Professor Edward Ross.

Narayan returned from the US to India in late 1929 as a Marxist. He joined the Indian National Congress on the invitation of Jawaharlal Nehru in 1929; Mahatma Gandhi became his mentor in the Congress. He shared a house at Kadam Kuan in Patna with his close friend and nationalist Ganga Sharan Singh (Sinha). with whom he shared the most cordial and lasting friendship.

After being jailed in 1932 for civil disobedience against British rule, Narayan was imprisoned in Nasik Jail, where he met Ram Manohar Lohia, Minoo Masani, Achyut Patwardhan, Ashok Mehta, Basawon Singh (Sinha), Yusuf Desai, C K Narayanaswami and other national Leaders. After his release, the Congress Socialist Party, or (CSP), a left-wing group within the Congress, was formed with Acharya Narendra Deva as President and Narayan as General secretary.

When Mahatma Gandhi launched the Quit India Movement in August 1942, Yogendra Shukla scaled the wall of Hazaribagh Central Jail along with Jayaprakash Narayan, Suraj Narayan Singh, Gulab Chand Gupta, Pandit Ramnandan Mishra, Shaligram Singh and Shyam Barthwar, with a goal to start an underground movement for freedom. Many young socialist Leaders like Dr Ram Manohar Lohia, Chhotubhai Puranik, Aruna Asaf Ali, etc. took part in underground movement. As Jayaprakash Narayan was ill, Yogendra Shukla walked to Gaya with Jayaprakash Narayan on his shoulders, a distance of about 124 kilometres. He also served as the Chairman of Anugrah Smarak Nidhi (Anugrah Narayan Memorial Fund).

Between 1947 and 1953, Jayaprakash Narayan was President of All India Railwaymen's Federation, the largest labour union in the Indian Railways.

Narayan returned to prominence in State politics in the late 1960s. 1974 ushered in a year of high inflation, unemployment and lack of supplies and essential commodities. Nav Nirman Andolan movement of Gujarat asked Jayaprakash to lead a peaceful agitation. On 8 April 1974, aged 72, he led a silent procession at Patna. The procession was lathi charged. On 5 June 1974, Jayaprakash addressed a large crowd at Gandhi Maidan in Patna. He declared, "This is a revolution, friends! We are not here merely to see the Vidhan Sabha dissolved. That is only one milestone on our journey. But we have a long way to go... After 27 years of freedom, people of this country are wracked by hunger, rising prices, corruption... oppressed by every kind of injustice... it is a Total Revolution we want, nothing less!" In 1974, he led the students' movement in the state of Bihar which gradually developed into a popular people's movement known as the Bihar Movement. It was during this movement that JP gave a call for peaceful Total Revolution. Together with V. M. Tarkunde, he found the Citizens for Democracy in 1974 and the People's Union for Civil Liberties in 1976, both NGOs, to uphold and defend civil liberties.

Indira Gandhi was found guilty of violating electoral laws by the Allahabad High Court. Narayan called for Indira and the CMs to resign and the military and police to disregard unconstitutional and immoral orders. He advocated a program of social transformation which he termed Sampoorna kraanti, "total revolution". Immediately afterwords, Gandhi proclaimed a national Emergency on the midnight of 25 June 1975. Narayan, opposition Leaders, and dissenting members of her own party were arrested that day.

Indira Gandhi revoked the emergency on 18 January 1977 and announced elections. The Janata Party, a vehicle for the broad spectrum of the opposition to Indira Gandhi, was formed under JP's guidance. The Janata Party was voted into power and became the first non-Congress party to form a government at the Centre. On the call of Narayan, many youngsters joined the JP movement.

Narayan died in Patna, Bihar, on 8 October 1979, three days before his 77th birthday, due to effects of diabetes and heart ailments. In March 1979, while he was in hospital, his death had been erroneously announced by the Indian prime minister, Morarji Desai, causing a brief wave of national mourning, including the suspension of parliament and regular radio broadcasting, and the closure of schools and shops. When he was told about the gaffe a few weeks later, he smiled.