Floyd Mayweather Jr.

Floyd Mayweather Jr. earned more money per minute of athletic competition than any human being in history. His 50-0 professional record includes two fights that each generated over $400 million in total revenue: the Pacquiao fight in 2015 ($600M+ gross) and the McGregor fight in 2017 ($550M+ gross). Mayweather's personal take from those two bouts alone exceeded $500 million. He was the highest-paid athlete in the world multiple times, and his nickname -- Money -- was not ironic.

Mayweather's financial genius was in controlling his own promotion. Through Mayweather Promotions, he cut out the middleman and took the promoter's share on top of the fighter's share. He negotiated his own pay-per-view deals, set his own fight terms, and effectively became his own media company. The result was fight purses that dwarfed anything in boxing history. His guaranteed purse for the McGregor fight was $275 million -- before pay-per-view bonuses.

The exhibition era has been equally lucrative. Post-retirement, Mayweather has fought YouTubers, MMA fighters, and lesser-known boxers in exhibition bouts around the world, reportedly earning $20-100 million per appearance. He treats these events as recurring revenue, flying to Dubai, Tokyo, or London for a single night's work. Critics call it a circus. Mayweather calls it business. Either way, the cash register keeps ringing.