Newcastle are on the lookout for new owners, with Mike Ashley keen to cash in and Amanda Stavely's consortium having so far failed in talks to buy the 'Magpies'.
As reported in 'The Star on Sunday', Mayweather expressed his admiration for the 'party city' and refused to rule out making a takeover bid of his own.
"You better believe if I were to invest in I would be back partying there often," Mayweather joked.
"I love Newcastle, those guys like to party as hard as any city I have been to anywhere in the world.
"I met some of the players last year and they are good guys. I am always open to new business opportunities and I love all sports, but I invest with my head not my heart.
"Investing with your heart is the quickest way to lose money. But if somebody put together a business plan and my people looking over it and went 'Floyd that can make money' then I would invest. Soccer might not be my game but I've got connections everywhere.
"Cristiano Ronaldo has been a long-time supporter and buddy of mine, so I might even be able to get him to finish his career off at Newcastle."
Should Mayweather's interest be real, it is likely to depend largely on Newcastle avoiding relegation, with the club currently sat in 13th place in the Premier League with right games to play.