The UFC superstar has leapt 20 places from last year's list, when he was in 24th place after raking in $34 million. This time, Forbes estimates his income at $99 million, thanks largely to the massive pay day he received for fighting Floyd Mayweather last summer.
That accounted for $85 million of McGregor's pay in the past year, with the rest coming from endorsements. Forbes puts the income from those at $14 million.
The Irishman signed a slew of deals over the past 12 months with the buzz around the Mayweather fight. His current partners are Burger King, Beats by Dre, Monster Energy, David August, BSN, Anheuser-Busch, HiSmile and Betsafe.
He also has a residency deal with the Wynn Las Vegas for all of his afterparties, and his digital properties, Conor McGregor FAST Program, MacMoji App, MacTalk App and the Mac Life, also generate cash.
LeBron, meanwhile, is sixth on the list, with an estimated $85.5 million income. The Cavs superstar is not just making money from basketball and endorsements, he's also a totally legit business tycoon.
He was an early investor in Blaze, and his investor group owns 17 of the fast-growing franchises. James' Nike signature sneakers are the best-selling among active NBA players. He has his own production company (SpringHill Entertainment) and media company (Uninterrupted).
Even his 2% stake in Liverpool, acquired through his partnership with Fenway Sports Group, is soaring in value with the English club reaching the Champions League Final for the first time since 2007.
The top spot on the list belongs yet again to Floyd Mayweather, who worked for one night in 2017 and made $275 million. He added $10 million on top of that with endorsement deals.
Next on the list are the two most famous soccer players in the world, Lionel Messi and Cristiano Ronaldo. Messi pulled in $111 million in the last year as the highest paid soccer player in the world. Ronaldo finished just behind him with $108 million.
That means McGregor's prediction that he would one day out-earn Ronaldo hasn't yet come to pass. He's getting closer than many though he ever would though.