The Italy icon weighed in on the conversation regarding the Barcelona and Real Madrid stars, giving the slight edge to the Blaugrana maestro.
Both the Barcelona ace and Real Madrid star have started the season in superb form, with each player netting a hat trick in the Champions League in midweek, and Cannavaro feels the Argentine has the edge on the Portugal captain - though he considers the 28-year-old's Brazilian namesake to be the game's greatest ever.
"In my career, Diego Maradona had the biggest influence on me," Cannavaro told 21CN. "But I think there is another player who might be even greater. That’s the Brazilian Ronaldo.
"However, both Messi and Ronaldo are great players in terms of scoring. At this very moment, Messi is a little bit better.
When asked about the best defenders in the world, Cannavaro, who captured the FIFA World Player of the Year and captained Italy to the World Cup crown in 2006 as a center back, singled out PSG's Thiago Silva.
"I like Thiago Silva very much too," Cannavaro said. "He has great skills and physicality, one of the best center backs these days."
Cannavaro, who hung up his boots in 2011, is currently assistant coach at Al-Ahli in Dubai but admits he would be "honored" to be considered for a role in the Italian national team set-up.
"I’m very honored and delighted that my name is on their list, but right now I can’t say anything because it is not up to me to decide," Cannavaro said. "But I would definitely be very honored if I were chosen someday. I haven’t been a coach for very long, I’m still learning."
The retired Cannavaro enjoyed an illustrious career, representing Juventus, Madrid and Inter, as well as winning 107 caps for Italy.