They replace Russian business magnate Alisher Usmanov after the Arsenal shareholder saw his fortune fall to 10.65 billion.
The richest Briton, the Duke of Westminster, is ranked 10th on the list after his fortune rose to 8.5 billion.
Last year, 88 billionaires were living in the UK, worth a total of more than 245 billion. In 2004, the number was 30, with a combined wealth of 65 billion.
Among the new members of the billionaire club is West End producer Sir Cameron Mackintosh, who saw his fortune rise by 175 million in the last year and is now worth 1 billion.
Sports Direct founder Mike Ashley and Sir Richard Branson are also among the UK's top 25 wealthiest.
Seventy two billionaires are now based in London, compared with 48 sterling-equivalent billionaires in Moscow, 43 in New York, 42 in San Francisco, 38 in Los Angeles and 34 in Hong Kong.
- AAP