Liverpool forward Coutinho has become a key figure at Anfield since joining from Inter in January 2013.
The Brazil international's performances on Merseyside have drawn admiring glances from elsewhere, with Madrid's LaLiga rival Barcelona having been previously linked.
And Ronaldo, who spent five years at the Bernabeu, would be keen for Coutinho to follow his lead of playing in Madrid.
"I would like to see Coutinho at Real Madrid, the Liverpool player," the former Brazil star told Onda Cero.
The 40-year-old also stated that there is little to separate Cristiano Ronaldo from Barcelona trio Lionel Messi, Luis Suarez and Neymar when it comes to deciding who is the best player in the world.
"Ronaldo, Messi and Neymar are all great players - and I would include Suarez in that list as well," he added.
"We often forget that they are all great players when we are talking about who is the best. It is very hard to say who is the best.
"I am going to say Cristiano, because he plays for Madrid. But we cannot ignore how good the others are. We have to respect them."