Ronaldo and Messi are widely considered the best players on the planet, with the pair winning the last seven Ballon d'Ors between them.
Courtois feels Hazard, 24, can also one day claim Fifa'a top individual playing prize.
"Yes, of course. He's still not at the level of Messi and Ronaldo, who are head and shoulders above all the other players. But Eden has the potential to get there," Courtois said of his Belgium and Blues teammate to RMC.
"He's only 24 years old. He can still improve. He has the potential to be a future Ballon d'Or. But as long as Messi and Ronaldo play like that, scoring 30 goals in 30 matches, it won't be easy."
Hazard has scored 14 goals and provided 13 assists in 40 appearances for the Blues this season.