According to Forbes, the Juventus star made $105 million (£83m) before tax in the last year, taking his total worth over the $1 billion (£789m) mark.
The 35-year-old attacker has been named the fourth-highest earning celebrity in 2020 by the magazine, behind tennis legend Roger Federer, rapper Kanye West and Kylie Jenner.
Barcelona talisman Lionel Messi, who Forbes said earned $104m (£82m) in the last year, came in fifth while Paris Saint-Germain forward Neymar took seventh place with $95.5m (£75m).
After golf icon Tiger Woods and former boxer Floyd Mayweather, Ronaldo is just the third athlete ever to accumulate such wealth and the first to do so in a team sport.
The Portugal international is said to have made $650m (£513m) in wages over his 17 years as a professional athlete, with the rest made from endorsements. He has been tied to a lucrative lifetime deal with Nike since 2016 and is attached to several other big-name brands.
The five-time Ballon d’Or winner is also building a business empire, with his fashion and lifestyle brand, hotel chain and the CR7 museum in his hometown of Funchal in Madeira.
His 2020 earnings have been hit by the coronavirus pandemic, as his salary has dropped after the Juventus squad agreed to take a 30 percent pay cut.
Although Messi’s salary this year was drastically reduced by 70% because the crisis, Forbes predicts the Argentine sensation will join his eternal rival in the billionaire’s club next year.
Having been on hiatus since March, Serie A will return later this month, with Juve facing an away trip to Bologna on their first game back on June 22. They will then host Lecce four days later.
The Turin giants are a point ahead of Lazio in Serie A with 12 games left to play.
Maurizio Sarri’s team are chasing down a ninth consecutive title, while Ronaldo is trailing Lazio star Ciro Immobile in the goal charts.
The Portugal hero has netted 21 times in 22 games, while Italy international Immobile is on 27.