Mayweather finished his career with a record of 50 wins (27 by KO) and 0 losses.

"I think my grandmother saw my potential first," he once said in an interview. "When I was young, I told her, 'I think I should get a job.' She said, 'No, just keep boxing.'"

Mayweather had an amateur record of 84-8 and won national Golden Gloves championships in 1993 (at 106 lb), 1994 (at 114 lb), and 1996 (at 125 lb).

Mayweather won a bronze medal in the featherweight division at the 1996 Olympics. In his semifinal bout against eventual silver medalist Serafim Todorov of Bulgaria, Mayweather lost by a controversial decision. The U.S. team filed a protest over the bout, claiming that Mayweather landed punches that were not counted, while Todorov was awarded points without landing a punch. "You know and I know I wasn't getting hit," Mayweather said afterward. "They say he's the world champion. Now you all know who the real world champion is."

In 1998, he won the WBC super featherweight (130 lb) championship with an eighth-round technical knockout of The Ring world #1-ranked super featherweight Genaro Hernández. It was Hernández' first defeat in that weight class. He said after the fight, "He defeated me, he is quick, smart and I always knew he had the speed. I give him respect. He is a true champ".

Although he originally bore the nickname "Pretty Boy," Mayweather would later re-brand himself as "Money" and he more than lived up to the moniker, showing off his possessions--including cars, watches, and stacks of cash--on his social media pages.

Mayweather fired his father as his manager and replaced him with James Prince. A few months after the fight, the rift between father and son grew when Mayweather also fired the elder Mayweather as his trainer.

Floyd Mayweather Sr. negotiated to train Oscar De La Hoya and be in his corner during the fight against his son, but De La Hoya decided to train with Freddie Roach instead. Mayweather Jr. won the fight by a split decision in 12 rounds, capturing the WBC title.

Floyd Mayweather went his whole career without being knocked out, but there was one time he was technically knocked down. In 2001, the 43-year-old Mayweather took a count in a bout against Carlos Hernández. It occurred in the sixth round after Mayweather clocked the Salvadoran fighter with a left hook. Mayweather moved his hands to the canvas, complaining about his hand which ended up being ruled as an official knockdown for Hernández.

Mayweather jumped a security barricade and attacked Big Show to help Rey Mysterio, whom Show had threatened to chokeslam. The attack resulted in Big Show receiving a broken nose. The following night on Raw, Big Show challenged Mayweather to a one-on-one No Disqualification match at WrestleMania XXIV, which Mayweather accepted. At WrestleMania, Mayweather defeated Big Show in a knockout with brass knuckles to maintain his unbeaten record.