One Direction, who came third in 2010, are in a league of their own in the No 1 spot with the boyband on track to hit close to €1bn by the end of the year.
Jedward — who came sixth in 2009 — rank fifth in the Rich List compiled by Now magazine, which estimates the bank balance of the brothers at just €6m.
The twins — who are managed by Louis Walsh — have stunned critics by becoming among the wealthiest of all the X Factor contestants.
“The Grimes twins, 21, raked in €1.2m for their Celeb Big Brother appearance and have plugged everything from kebabs to Shake n’Vac,” said the poll.
The Now poll also reported that the siblings have forked out almost €600,000 on two Ferraris.
Leona Lewis is in second place with an estimated wealth of €14m since winning seven years ago, while the show’s other big female winner Alexandra Burke is in third place with over €7m since her famously teary victory in 2008.
JLS — who were mentored by Louis Walsh — are worth over €7m each since coming runners-up in 2008.
Little Mix — who won the show in 2011 under the guidance of Tulisa — are said to be worth just short of €4m.
Popstar Olly Murs and TV presenter Stacey Solomon came in second and third place in 2009 behind the winner Joe McElderry, but they both beat the singer in the cash stakes with both of them earning an estimated €3.8m in the last four years.
Olly Murs, who is ranked in seventh place, owes his fortune to 10 million record sales, a tour with Robbie Williams and Stateside success.
The year Jedward first burst onto the X Factor stage in front of a horrified Simon Cowell in 2009 also proved to be one of the show’s most successful years, with four of the contestants making it into the poll.
The winner that year, Joe McElderry, makes the rich list at No 17 after managing to become a millionaire.