Mr Floyd died last Monday after a white police officer held him down by pressing a knee into his neck and sports stars have joined in the widespread condemnation.
Mayweather Promotions confirmed that the former five-division world champion had reached out to Mr Floyd's family with an offer to cover all costs relating to the funeral.
Hollywood Unlocked reported that Mayweather was distraught to learn that the former officer Derek Chauvin was facing the minimal charge, third-degree murder, after video of the incident was widely shared, prompting him to contact the family through a mutual friend.
In a tweet, Mayweather Promotions shared the link to the Hollywood Unlocked story and confirmed its accuracy.
Several stars from the world of sport have sent anti-racism messages as protests following Mr Floyd's death have taken place over the past week.
On Monday, England striker Marcus Rashford and his Manchester United team-mate Paul Pogba posted messages, while a number of Liverpool players - including captain Jordan Henderson and Virgil van Dijk, tweeted messages alongside an image of the squad taking a knee on the centre circle at Anfield.
Tiger Woods added his voice on Tuesday morning. In a post on social media, the 15-time major winner wrote: "My heart goes out to George Floyd, his loved ones and all of us who are hurting right now. I have always had the utmost respect for our law enforcement.
"They train so diligently to understand how, when and where to use force. This shocking tragedy clearly crossed that line. I remember the LA riots and learned that education is the best path forward.
"We can make our points without burning the very neighborhoods that we live in. I hope that through constructive, honest conversations we can build a safer, unified society."