Ronaldo has seen his future in the Spanish capital called into question on a regular basis during the summer transfer window, with it suggested that he could be lured back to Manchester United for a second spell at Old Trafford.
He still has two years left to run on his current contract, but Real are yet to put an extension in place - fuelling the exit rumours.
The La Liga giants are, however, doing all they can to keep the Portugal international on their books, and Ancelotti is confident an agreement will be reached.
He told a press conference on Saturday: "Everyone knows that he is a superstar and a great player.
"The most important thing for the club is that a player of his quality shows the utmost professionalism. That is good, especially for the young players who can see a world-class player working with that attitude.
"I am not responsible for the renewal of his contract, but it won't be a problem."
Ronaldo is not the only high-profile figure at Santiago Bernabeu to be linked with an imminent exit, but Ancelotti claims there is no guarantee that the likes of Kaka, Gonzalo Higuain - who has been linked with Arsenal and Chelsea - and Fabio Coentrao - who is said to be interesting Tottenham Hotspur - will be on the move.
He added on Kaka: "He is a Real Madrid player and he has started well, just like the rest. He is very confident and looking forward to the season. Let's see what happens, he knows that he has to perform better than last year.
On Huguain, he said: "I have spoken to the player, but it was a private conversation. He is currently a Real Madrid player and I am happy to have him here."
And on Coentaro, he added: "I spoke to him and I can say the same as in the case of Higuain. He is currently a Real Madrid player and I am happy to have him here.
"He is a quality left-back; there are many games this season and I think he is a useful player for the squad."