The Portugal winger, who joined Madrid from Manchester United during the offseason, said Tuesday in an interview with France Football magazine that Barcelona players have the best chances to win the prestigious trophy this year.
"Messi is the favorite," Ronaldo said. "Why not him? If he wins it, it will be well deserved."
Six players from Spanish and European champion Barcelona are chasing the Golden Ball, whose list of nominations was released last week and included Messi, Xavi Hernandez, Thierry Henry, Andres Iniesta, Yaya Toure and Zlatan Ibrahimovic.
Ronaldo has also been selected. The winner will be announced on Dec. 1.
"The favorite is a player from Barcelona," Ronaldo said. "To win a trophy like this, you need to have won collective trophies, a league title, the Champions League. That's why many players from Barcelona could win it."
Restricted to players in Europe, the Golden Ball winner is decided by an annual poll of football journalists compiled by the magazine.
Ronaldo also admitted that Barcelona was better than Real Madrid.
"But why? Because they are playing together for several seasons," the Portugal winger said. "Not just for two months like us. We respect Barcelona but let's wait until the end (of the season)."
