Jim Ratcliffe, 65, chief executive of Ineos, topped the Sunday Times Rich List with a fortune of £21.05 billion, leapfrogging his way from 18th place year.
Mr Ratcliffe, whose firm is currently locked in a legal battle with the Scottish government over its moratorium on fracking, emerged in pole position after additional details led to a “substantial revaluation” of his assets.
The Sunday Times has previously described him as publicity shy.
Ineos’s director Andy Currie and finance director John Reece shared in his fortunes, joining Ratcliffe in the top 20, taking joint 16th place with fortunes of £7 billion each.
At second place were the Hinduja brothers, Sri and Gopi, worth £20.64 billion.
Their fortune jumped by £4.44 billion on 2017, with their India-based car manufacturer Ashok Leyland and Mumbai-based IndusInd Bank having a particularly successful year.
British-American industrialist-turned-media mogul Sir Len Blavatnik came in third place with £15.26 billion to his name.
The 60-year-old was knighted this year for services to philanthropy - recent donations include £50 million to fund the Tate Modern’s new wing, and £5 million towards the Victoria and Albert Museum’s new entrance, as well as funding the Blavatnik School of Government at Oxford University.
This year is the 30th anniversary of the Rich List, with the top 20 now worth a combined £218.6 billion - increasing their cumulative wealth by £33. 5 billion in the last year.
Of the 1,000 people on the list, 145 are billionaires.
There are now 141 women on the list, with Charlene de Carvalho-Heineken of the brewing dynasty ranked highest at number six.
She and her financier husband Michel de Carvalho - vice chairman of Citigroup - increased their wealth by almost 20% over the past year to £11.1 billion.
Elsewhere, Arcadia boss Sir Philip Green’s fortune took a tumble - his reputation was dragged through the mud following the collapse of BHS after he sold it to a man twice declared bankrupt for just £1.
It later emerged that the department store’s two pension schemes had a combined shortfall of £571 million, risking the future of their 19,000 members and prompting MPs to call Sir Philip to give evidence in front of a parliamentary select committee.
Falling sales at his flagship brands Topshop and Miss Selfridge as well as his promise to contribute £363 million towards the pension deficit led to Sir Philip’s fortune dropping by £787 million to £2 billion.
Celebrity chef Jamie Oliver exited the list completely following a rocky year for his eponymous restaurant empire - it is still undergoing restructuring after racking up debts of more than £70 million.
In January the chain announced 12 of its 37 branches were to close.
Financier Ernesto Bertarelli and his wife Kirsty saw the biggest decrease in wealth, losing £1.48 billion due to falls in Ernesto’s pharmaceutical company stakes, the list’s author said.
The couple are now 11th on the list.
Aristocrat Hugh Grosvenor is still the UK’s youngest billionaire at the age of 27 having inherited his fortune and his title - 7th duke of Westminster - following the death of his father two years ago.
His property empire includes 300 acres in Mayfair and Belgravia, as well as properties in Oxford, Cheshire, Scotland and Spain.
His wealth grew by £444 million in the last year to £9.96 billion.
Robert Watts, who compiled the list, said: “Britain is changing. Gone are the days when old money and a small band of industries dominated the Sunday Times Rich List.
“Aristocrats and inherited wealth has been elbowed out of the list and replaced by an army of self-made entrepreneurs.
“Today’s super rich include people who have set up businesses selling chocolate, sushi, pet food and eggs.
“We’re seeing more people from humble backgrounds, who struggled at school or who didn’t even start their businesses until well into middle age.
“Meanwhile, technology is also playing a bigger part in helping more young people make their fortunes and small companies to grow.
“Britain’s rich are getting richer, but the cast of Britain’s 1,000 richest people is an ever-changing and increasingly diverse cast of people.”