The latest edition of the list which is published each year by the Sunday Times newspaper, put Denise, John and Peter Coates and family in 16th position with a total worth of £8.80bn (€10.13bn/$10.97bn).
This was the same place as in the 2022 list, with Coates and her family having accumulated an additional £158m in wealth since the last list was published.
The Coates family were ranked between XTX Markets chief executive Alex Gerko in 15th with £9.13bn and Bestseller and Asos CEO Anders Holch Povlsen in 16th place with £8.50bn.
Coates founded Bet365 in 2001, borrowing £15.0m against her family’s betting shop estate to launch the online gambling brand.
India-born businessman Gopi Hinduja, whose Hinduja Group owns a number of companies such as Gulf Oil International and IndusInd Bank, topped the list with a fortune of £35.0bn.
Sir Jim Ratcliffe, the CEO of Ineos chemicals group who has been linked with a takeover of Premier League football club Manchester United, was second on £29.69bn.
In third was Sir Leonard Blavatnik, who found his fortune in investment, media and music, with £28.63bn.