Thanks to the retirement of boxer Floyd Mayweather and injuries hampering the career of golfer Tiger Woods, Ronaldo took the top spot with annual earnings of $88 million (£61 million).
It's only the second time an athlete from a team sport has topped Forbes' list since it began ranking sports earnings in 1990 - the first being basketball player Michael Jordan.
Ronaldo has commercial endorsements to thank for getting him the top spot - they make up a massive $32 million (£22 million) chunk of his income.
As well as a $13 million (£9 million) a year contract with sportswear giant Nike, Ronaldo also has deals with Tag Heuer, Herbalife, Pokerstars, Clear Shampoo - as well as his own range of cologne and menswear.
Part of the attraction companies have for Ronaldo is his huge social media presence: 43 million followers on Twitter and 112 million "likes" on Facebook. Forbes estimates that all of this adds up to $176 million (£122 million) in media value for all his promotional posts.
There's also, of course, his Real Madrid contract, which pays $50 million (£35 million) a year in salary and bonuses. Ronaldo's record for the club suggests it was money well-spent - since joining in 2009 he's scored 260 goals and helped win the team two Champions Leagues.
Spain is obviously good to its footballers: Lionel Messi of Barcelona came second on the list, with earnings of just over $81 million (£56 million) while racing driver Lewis Hamilton - the
Here's Forbes' rundown on the top ten earning athletes of the last 12 months:
- Cristiano Ronaldo - Football $88m (£60.6m)
- Lionel Messi - Football $81.4m (£56.1m)
- LeBron James - Basketball $77.2m (£53.2m)
- Roger Federer - Tennis $67.8m (£46.7m)
- Kevin Durant - Basketball £56.2m (£38.7m)
- Novak Djokovic - Tennis $55.8m (£38.46m)
- Cam Newton - American Football $53.1m (£36.6m)
- Phil Mickelson - Golf $52.9m (£36.46m)
- Jordan Spieth - Golf $52.8m (£36.39m)
- Kobe Bryant - Basketball $50m (£34.46m)