Bookies had to pay out 10 million pounds after Royal Wedding won by three lengths in steeplechase at Fontwell, Sussex.
Having odds of 4-1, the horse was backed by millions of "hunch" punters, The Sun reported.
The horse won the race barely six hours after William and Kate tied the knot at Westminster Abbey.
"This horse has given us bookies a massive kick in the crown jewels. Royal Wedding backers are over the moon.
"Loyal royalists who kept the faith have scooped a small fortune," a spokesman of the betting firm Ladbrokes was quoted as saying.
Royal Wedding was not the only aptly named horse to score a win.
A horse called Party Politics won the Grand National just five days before the 1992 General Election.
In 1973 when Princess Anne married Captain Mark Phillips, a horse called Royal Mark had won.
Published 30 April 2011, 08:49 IST