Gaur was born in village Chirchitta, Bulandshahr in Uttar Pradesh. His Father was an agricultural inspector. He graduated in civil engineering from the University of Roorkee in 1950.
After graduation, Gaur joined the state government's irrigation department as a junior Engineer. Subsequently he started his own venture as a civil contractor. Two decades later, he laid the foundation for the Jaypee Group by setting up Jaiprakash Associates, a civil engineering and construction company. To leave a secure government job and pursue contractorship in 1958, when it was considered to be most prestigious, required courage. In 1967, he led and transformed a motley group of persons into a company which took pride in its cable address "Iron Will" and went on to execute:
In 2010 he was ranked by Forbes magazine as the 48th-richest person in India, with an estimated wealth of US$1.5 billion.