Ambani, 62, maintained a place in the top 10 for the second time after a $13 billion or 24 per cent surge in his wealth to $67bn.
"The only Asian in the Top 10, Ambani's wealth increased mainly on the back of a good performance in his telecom business," the Hurun Rich List said.
Ambani is restructuring Reliance Industries to facilitate the planned strategic investments in group businesses - Reliance Jio, Reliance Retail, refining and petrochemicals. The conglomerate aims to be a zero net debt company in 18 months and is in discussion to sell 20 per cent oil-to-chemicals business to Saudi Aramco, at an enterprise value of $75 billion. RIL became the first Indian company to hit the milestone of achieving Rs 10 lakh crore market capitalisation.
Amazon CEO Jeff Bezos retains the top spot in the Hurun Global Rich List 2020 with $140 billion, down $7 billion, mainly due to the world's largest divorce settlement with former wife MacKenzie Bezos, who makes the list in her own right with $44 billion.
Amazon is one of four companies, whose valuations have hit $1 trillion, the others being Microsoft, Apple and Google. Bezos bought a $165 million home, setting a new record for Los Angeles. In February, he pledged $10 billion to help fight climate change.
Bill Gates, dropped down to third place on the Hurun Global Rich List 2020, with $106 billion, despite growing his wealth $10 billion or 10 per cent. Last month, Gates announced a $100 million commitment to fight coronavirus which has triggered a global health emergency.
Over the past two decades, the Bill and Melinda Gates Foundation has given out more than $50 billion to global health and education.