That’s according to Spanish news outlet Don Balon who say the Portuguese superstar has been reassuring his team-mate.
Benzema has faced criticism in recent weeks and Real are repeatedly linked with top attacking talent.
But Don Balon say Ronaldo has told the Frenchman that he has his full support.
Reports last week suggested Ronaldo met with club supremo Florentino Perez and told him in no uncertain terms that Benzema should not be sold.
Real Madrid star Cristiano Ronaldo in secret talks with France international
The 32-year-old believes Benzema would be tough to replace and enjoys playing alongside him at Real.
Spurs striker Harry Kane has been touted as a potential arrival at the Bernabeu and if he were to sign he would likely replace the experienced ace.
But Ronaldo is desperate for Benzema to stay even if Real supporters might prefer him to leave.
The 29-year-old has scored just twice in his nine appearances in all competitions so far this season.
Former Barcelona striker Gary Lineker branded Benzema as overrated following Real’s 1-1 draw against Tottenham in the Champions League.
He tweeted: “Is it me or is Benzema a tad overrated?
“A goal every other game in a team as strong as Real Madrid is nada especial.
“Decent not great.”
Real Madrid return to La Liga action against Eibar tomorrow as they look to close the gap on leaders and arch rivals Barcelona.