Share
The number is calculated by combining his total number of followers across Instagram, Facebook, Twitter, YouTube, and Chinese social media sites Weibo and Kuaishou.
It does not equate to one billion individual followers, as many people will follow him across multiple platforms, and some will be fake accounts, known as bots.
On the pitch, Ronaldo was famed for his rivalry with Argentinian star Lionel Messi.
But off it, there is no competition for who is winning the social media contest - Messi has a mere 623 million followers.
It's not just sport: Ronaldo is also ahead of some of the biggest names in entertainment, including singers Justin Bieber, Taylor Swift and Selena Gomez.