Forbes reported that Mayweather, 41, topped sports highest-earners after banking $275 million dollars from his cross-combat superfight against mixed martial arts star Conor McGregor in August 2017.
With an additional $10 million in endorsements, Mayweather earned a total of $285 million between June 1 2017 and June 1 2018, comfortably eclipsing the second-placed figure on the list, football star Lionel Messi, who made $111 million.
However, female athletes notably failed to break into the top 100 for the first time since Forbes began publishing its ranking.
Tennis star Serena Williams, who last year was the only woman to feature on the list at 51st place with earnings of $27 million, dropped out of the rankings after taking a break from the sport due to the birth of her daughter.
Former welterweight king Mayweather, who came out of retirement to face McGregor in Las Vegas, topped the rankings for the fourth time in seven years.
McGregor meanwhile vaulted up the rankings to fourth spot, thanks to his $85 million cut of the Mayweather purse.
A further $14 million in endorsements took the Irish fighter’s earnings to $99 million, just behind Real Madrid soccer star Cristiano Ronaldo, who was third with earnings of $108 million.
Brazilian footballer Neymar was fifth on the list with $90 million in earnings, his salary boosted by his record-breaking transfer from Barcelona to Paris Saint-Germain last year.
NBA icon LeBron James was the highest-paid basketball player to feature on the list, coming in at sixth with total earnings of $85.5 million, just ahead of men’s tennis king Roger Federer, who earned $77.2 million.
Swiss ace Federer remains the most attractive athlete for sponsors, with endorsement deals accounting for $65 million of his earnings.
Golden State Warriors star Stephen Curry was the only other NBA player to feature in the top 10, with earnings of $76.9 million.
Atlanta Falcons quarterback Matt Ryan is the highest earning NFL player, coming in at ninth with $67.3 million. Ryan’s earnings were swollen by a $45 million dollar signing bonus after he agreed a new contract earlier this year.
Another NFL quarterback, the Detroit Lions’ Matthew Stafford rounded out the top 10 with $59.5 million.
Elsewhere, Britain’s Formula One world champion Lewis Hamilton is the highest paid figure from motorsport to feature, coming in at 12th with $51 million.
Tiger Woods, who has not won a tournament for five years and who has barely played over the previous three seasons, remains the highest earning golfer with $43.3 million, with $42 million of it coming through endorsements.