Mayweather earned $85 million for fighting twice in the past 12 months while his possible future foe Manny Pacquiao, who ranked second in the list, made $62 million for the same period, according to Forbes.com.
Golfer Tiger Woods came in third with $59.4 million after almost consistently topping the top 100 list since 2001.
Last week Mayweather, through his lawyers, filed a motion before the court headed by Justice of the Peace Melissa Saragosa for serving the remainder of his term under house arrest instead of completing the same at the Clark County Detention Center in Nevada.
Among other things, Mayweather cited the "inhumane" condition inside his cell and his inability to perform his usual physical conditioning.
Early this week, Judge Saragosa rejected Mayweather's motion
, saying adequate or "sufficient space and time for physical activity are available if he so chooses."
Mayweather is expected to be discharged first week of August unless his term is cut for good behavior.
Meanwhile, Pacquiao has returned to his province in the Philippines from the US over the weekend to assist calamity victims in his home province, leaving behind his family who are vacationing in California, following his controversial fight against Bradley in Las Vegas, Nevada, last June 9.
Pacquiao lost to Palm Spring boxing star Timothy Bradley in a controversial split decision by the judges despite his overwhelming lead in points based on CompuBox
Pacquiao has accepted the verdict and urged his followers to respect the decision of the judges.