"I have decided to permanently retire from boxing," Mayweather said in a statement released in Las Vegas. "This decision is not an easy one for me to make as boxing is all I have done since I was a child.
"However, these past few years have been extremely difficult for me to find the desire and joy to continue in the sport."
Mayweather, 31, reached the peak of his career a year ago with a split-decision victory over Oscar De La Hoya. His only fight since then came against Ricky Hatton in December, a bout Mayweather won with a 10th-round TKO.
Mayweather won championships in five different weight divisions and captured a bronze medal at the Atlantic Olympics.
"There comes a time when money doesn't matter," Mayweather said. "I just can't do it anymore."