The cutoff to crack the world's 100 highest-paid athletes is $25 million this year, compared with $17.3 million five years ago.
Mayweather, who topped the list in 2018 and four times in seven years, only had an exhibition match last December in Japan and did not crack the top 100, which is comprised of athletes from 10 different sports.
Forbes calculates the athletes' earnings by adding up their prize money, salaries and endorsements between June 2018 and June 2019.
Portugal football star Cristiano Ronaldo, who switched from Spanish giants Real Madrid to Italian club Juventus at the start of the northern hemisphere season, is second on $164 million with Brazil's Neymar - who plays for French club Paris St-Germain - listed third with earnings of $158 million.
For the second successive year, Lionel Messi sits above arch-rival Cristiano Ronaldo in Forbes' latest rich list, ranking as the best-earning footballer across the globe.
Adams earned more than the likes of Super Bowl winning quarterback Tom Brady, Liverpool star Mo Salah and National Basketball Association all star centre Nikola Jokic.
Canelo, who defeated Gennady Golovkin last September to become the unified middleweight champion, inked a very lucrative deal last October, signing a five-year 11-fight contract with streaming network DAZN worth $365 million.
Manchester United's Paul Pogba is the highest earning Premier League player in 44th place with $33m (£25.9m).
The top three of the Forbes list is usually reserved for boxers, golfers, tennis players or the NBA's biggest stars.
USWNT wins most lopsided game in World Cup history
Alex Morgan scored a record-tying five goals and 21-year-old Mallory Pugh scored off of the bench in her Women's World Cup debut. There was no other way to describe the US defeating Thailand on Tuesday night to kick off their Women's World Cup title defense.
Iran to release Lebanese US resident convicted of spying
Over the past four years, Zakka's family members have repeatedly called on the Lebanese government to negotiate for his release. He was held in Evin Prison, notorious for holding political prisoners, dual-nationals and academics.
The World On Arirang
Health Secretary Matt Hancock has pitched himself as the face of a younger, modernising generation in the Conservative Party. A former banker who was elected to Parliament in 2010, he is a champion of the free-market, libertarian wing of the party.