The 46-year-old legend holds an untarnished 50-0 career record with his last career win coming against Conor McGregor in 2017.
Since hanging up his gloves, Mayweather has hit the exhibition circuit and recently fought John Gotti III in a bout that erupted into chaos when a brawl between both corners stopped the fight.
In 2020, Money appeared on ESPN and was asked to pick the best of the best from his sport, with Mayweather having legendary names such as Ali, Rocky Marciano and Joe Louis to choose from.
But he instantly named himself as top choice and explained why.
The American said: “He’s beat more world champions than any other fighter in a shorter time and less fights than any other fighter.
“Landed punches at the highest percentage and took less punishment. He’s been world champion 18 years in five different weight divisions.”
Regarding placing Ali in fifth, a man widely-regarded as the best of all-time, he said: “Ali, only one weight class and really lost to Ken Norton three times.
“What he did is he stood for a cause in an era when African-Americans didn’t stand up for their people.”
Mayweather also launched an extraordinary rant against Ali as he was named the best boxer of all time.