Ramdev was born on 25 December in a Yadav family in 1965 to Ram Niwas Yadav and Gulabo Devi at Hazaribag Ali Saiyad Pur village of Mahendragarh district, Haryana. Both of his parents were farmers. He claims he became paralyzed when he was two & half and was later cured by practicing Yoga. He studied Indian scripture, Yoga and Sanskrit in various Gurukuls (schools). He was the student of Acharya Baldevji in Gurukul Kalwa. Ramdev took sanyasi diksha and adopted the name Swami Ramdev from Swami ShankarDev Ji. While living in Kalwa Gurukul in Jind district, Haryana, Ramdev offered free yoga training to villagers. Then he moved to Haridwar in Uttarakhand, where he practiced self-discipline and meditation, and spent several years studying ancient Indian scriptures at Gurukul Kangri Vishwavidyalaya.

Ramdev founded the Divya Yog Mandir Trust in 1995. In 2003, Aastha TV began featuring him in its morning yoga slot. There he proved to be telegenic and gained a large following. A large number of people, celebrities from India & abroad attended his Yoga camps. He taught yoga to many celebrities like Amitabh Bachchan, Shilpa Shetty and in foreign countries including Britain, the US & Japan. He also addressed Muslim clerics at their seminary in Deoband, Uttar Pradesh. In 2006, he was invited by Kofi Annan to deliver a lecture on poverty alleviation at a United Nations conference. He is also the judge of a reality show 'Om Shanti Om.' Recently, a district court banned the sale of his biography, 'Journey from God man to Tycoon.'

In March 2005, 113 employees of Divya Yoga Mandir Trust began an agitation for minimum wages and employees's rights such as coverage under the Provident Fund and Employees' State Insurance schemes. A meeting resulted in an agreement between the workers, management and the district administration; management agreed to pay minimum wage and not to initiate disciplinary actions against the protestors and, in turn, the workers agreed that they would restore normalcy at the workplace. However, the Trust refused to take back some of the workers, accusing them of committing sabotage. Their case was taken up by the Centre of Indian Trade Unions (CITU), affiliated with the Communist Party of India (Marxist) (CPM).

In December 2006, Ramdev claimed to improve the condition of patients suffering with AIDS through yoga and Ayurvedic drugs sold by his Divya Yoga Mandir Trust. He also suggested that sex education should be replaced by yoga education, as a means of AIDS prevention. He told reporters that "Sex education in schools needs to be replaced by yoga education". As a consequence of these public statements, he was sent a cease and desist order by the Indian Union Health Ministry to avoid making such claims in the Future, and the civil society threatened legal action. In response, Ramdev modified his statement, saying that the claims were not directly his but those of patients who practiced yoga.

According to Newsweek magazine, Ramdev "detests gays". In July 2009, when the Delhi High Court gave a verdict on decriminalising homosexuality in Delhi, Ramdev said, "This verdict of the court will encourage criminality and sick mentality. This is breaking the family system in India. Homosexuality is not natural and can be treated. If the government brings this law, I will take this matter to the streets of Delhi in protest." In 2011, he petitioned the court to overturn the ruling. He said that gay sex "is against our Vedic culture" and that "I consider homosexuality unnatural and a mental disorder. A bad habit. Many people acquire bad habits and get addicted to them." Ramdev stated that homosexuality could be cured using "yoga, pranayam and other meditation techniques".

In 2010, Ramdev announced plans to form a political party called Bharat Swabhiman (India Pride). He said that it would contest every seat in the next national elections. A year later, he stated that, instead of forming a political party, he would influence politics by encouraging a groundswell of popular reaction. In 2014, Ramdev announced that Bharat Swabhiman intended to contest some constituencies in the general election of that year and to form alliances with some other parties. It was at this time that he voiced his support for Narendra Modi to become the next Prime Minister of India. His attempts to run yoga camps during that election campaign, allegedly to gain support for Modi, were stymied by the Election Commission of India (ECI) who determined that they were politically motivated. The ECI had also tried to control his use of camps in the Rajasthan and Madhya Pradesh state elections of 2013.

In April 2011, Ramdev called on the government to add punitive powers to the Jan Lokpal Bill, a bill to appoint an independent body that would investigate alleged government corruption. Ramdev announced he would go on an anshan (hunger-strike) at Ramilla Ground in Delhi, on 4 June 2011, to pressure the government into rooting out corruption and repatriating black money. A week before the scheduled fast, the government set up a committee, headed by the chairman of the Central Board of Direct Taxes, to suggest steps to curb black money and its transfer abroad.

On 10 August 2012, Ramdev launched another indefinite protest against the government's failure to take action against corruption and to bring back black money. He announced that his Future strategy depended upon the governmental response to his protest. Ramdev ended the fast at Delhi's Ambedkar stadium on 14 August 2012, and said he was returning to Haridwar. Seeking the defeat of the Congress Party in 2014, he said, "Congress hatao, desh bachao" (Remove Congress, save the country), adding that except for the Congress Party, all parties were together on the issue of black money.