Mayweather, who ranks No.1 for making $US85 million from two fights last year, is serving a three-month jail sentence for domestic battery in Las Vegas, having failed in a bid to serve the remainder of his time under house arrest.
While his doctors and co-manager warned that staying behind bars might cause irreparable damage to his fitness and risk his boxing career, the undefeated US fighter is expected to climb back into the ring, likely later this year.
But Mayweather will not be fighting Filipino icon Pacquiao in the mega-bout that boxing fans have sought for years.
Pacquiao, second on the list at $US62 million ($A61.45 million) from earnings and endorsements, lost to unbeaten US fighter Tim Bradley on July 9 and they are set to fight a rematch in November.
Tiger Woods, who had topped the Forbes list since 2001, fell to third with $US59.4 million ,his earnings off $US16 million from the previous year and by half since his peak in 2009, mostly due to lost endorsement deals.
It was in 2009 that Woods, a 14-time major champion chasing the 18 major titles won by Jack Nicklaus, had a sex scandal erupt that caused him to start his 2010 season late and suffered a 2011 nagged by injuries.
Miami Heat star LeBron James ranks fourth at $US53 million , the highest of 13 basketball players on the list.
Swiss tennis star Roger Federer was fifth at $US52.7 million followed by NBA star Kobe Bryant at $US52.3 million , US golfer Phil Mickelson at $US47.8 million , English football star David Beckham of the Los Angeles Galaxy at $US46 million and Portuguese football star Cristiano Ronaldo at $US42.5 million , with the top salary of any athlete in any league at $US20 million .
In total, the top 100 made $US2.6 billion .
Only two women, both tennis players, cracked the list – Russian star Maria Sharapova, the newest career grand slam winner after her French Open final triumph earlier this month, and China’s Li Na, the 2011 French Open champion.
Sharapova was 26th at $US27.9 million , thanks in great measure to huge global endorsement totals as well as $5.9 million in prize money over the past year.
Li was 81st overall at $US18.4 million , with seven new endorsement deals after becoming the first Asian-born player to win a grand slam singles crown.
Indian cricket star MS Dhoni ranked No.31 and compatriot Sachin Tendulkar was No.78.
Jamaican sprinter Usain Bolt, the reigning 100m and 200m Olympic champion and world record-holder who figures to be a top attraction at the London Olympics, was 63rd with $US20.3 million.