The Sunday Times, which published the list, says London has 72 residents whose fortunes exceed 1 billion pounds ($1.6 billion). That's well ahead of Moscow, at 48, New York, at 43, San Francisco at 42, Los Angeles at 38 or Hong Kong at 34.
The newspaper reports that Britain also has more billionaires per head than any other country, with one in billionaire for every 607,000 Britons versus one for every 1 million or so Americans.
The newspaper has long published an annual list of the Britain's richest people, but this was the first time it took the additional step of seeing how the country's overall standing compared to that of other countries.
Indian-born brothers Srichand and Gopichand Hinduja top the British list, with a 11.9-billion pound fortune. The two run the Hinduja Group, a global conglomerate.
The brothers replace last year's richest man, Alisher Usmanov, who has seen his fortune drop by 2.65 billion pounds to 10.65 billion - largely because of the decline of the ruble.
Other notables on the list are steel magnate Lakshmi Mittal, in third place, and Chelsea football club owner Roman Abramovich, who dropped from fifth to ninth.