The 'One Thing' boy band knocked Daniel Radcliffe into second place on the annual heat magazine Rich List, thanks to their amassed fortune of £59.33 million ($96m).
The 'Kiss You' hitmakers - Harry Styles, 19, Niall Horan, 19, Zayn Malik, 20, Liam Payne, 20 and Louis Tomlinson, 21 - made history as the first UK group to debut at Number One on the US Billboard chart
with their second album 'Up All Night.'
Lucie Cave, editor-in-chief of heat, commented: "One Direction are young, talented, staggeringly good looking and adored by millions. To that we can now add 'rolling in cash.' No one said life was fair."
Meanwhile, Daniel - worth a whopping £56.18million ($91m) - scored the biggest pay check out of all the young stars on the list, thanks to the lucrative 'Harry Potter' franchise, but was knocked into second
place for the first time since 2010.
High profile Brits Robert Pattinson, Keira Knightley and Emma Watson all featured in the Top Five for the second year in a row.
The highest new entries were DJ Calvin Harris ($36m), model Rosie Huntington-Whiteley ($9.1m), singer Jessie J ($9.3m), 'The Amazing Spider-Man' star Andrew Garfield ($8.1m) and boyband JLS ($7.9mm).
'The Great Gatsby' actress Carey Mulligan was crowned this year's highest climber, up 10 places to number 19, while actor Aaron Taylor-Johnson jumped eight places to number 16.
A panel of celebrity experts analyzed the stars' financial earnings for the past year based on their TV and film deals, record sales and product endorsements.
The Top Five Richest British Celebrities under 30 are as follows:
One Direction ($96m)
Daniel Radcliffe ($91m)
Robert Pattinson ($72mm)
Keira Knightley ($60m)
Emma Watson ($45m)