The Argentina legend has raised eyebrows by offering his backing to the Real Madrid star and not his high profile compatriot.
The Real Madrid and Barcelona stars have been named alongside Bayern Munich winger Franck Ribery on a three-man shortlist for the prize, the winner of which will be announced January 13 in Zurich.
A recent poll of Goal readers saw Ronaldo come out on top of the voting for their selection to win the trophy and Maradona has now weighed in with his thoughts on the race to be crowned the world's best player.
"Cristiano Ronaldo should win. Messi has been injured a lot this year," the 53-year-old told Le Buteur.
Messi is the current holder of the Ballon d'Or and four-time winner of the trophy, but Ronaldo's incredible form since the start of the campaign has seen him emerge has the favorite to lift the award for a second time.
The Madrid forward has scored 17 goals in 15 Liga games already this season, while Messi has been hampered by a hamstring problem he first picked up in the latter stages of last season.