The results of a Heat study showed that, more than 30 years after they split up, The Beatles earned an estimated £55m, boosted by sales of their number one greatest hits album 1.
The fab four beat the likes of Irish supergroup U2 who came in second with an estimated £50m after the success of their latest album All That You Can't Leave Behind.
The magazine's second highest earner of the previous year, Sir Elton John, fell into third place with £35m.
While, among the relative newcomers, Westlife - who released their first single in the spring of 1999 - were the highest earning with £5m, just scraping into the top 10.
Heat editor Mark Frith said: "2000 was The Beatles's biggest money-making year yet - which is just incredible 30 years after they split.
"And really all they did was say 'yes' to the release of a compilation. That was a very profitable decision."
Frith told BBC News Online the figures were taken from record sales, revenue from tours and sponsorship and compiled by Music Week.
The Beatles's album 1, released in November 2000, has been number one in 30 countries and has simultaneously topped the charts in the UK and US.
By comparison, in 1999 - the first year Heat carried out their pop rich list survey - the group made an estimated £15m, coming in third place.
Last year's top earners, the Rolling Stones, were relegated to number four in the new survey with £27.5m.
While Sade's return from several years off the music scene is thought to have made her around £10m, putting her in sixth place.
Her Lovers Rock album fuelled her earnings but it was also due to the strength of her back catalogue with her Best Of album continuing to sell well.
The Spice Girls fell from sixth to ninth place with earnings of £5m in 2000, despite releasing their third album Forever.