The Italian coach says the Portuguese star is fundamental to the club going forward and attacker Gonzalo Higuain still has a part to play at the Santiago Bernabeu
The Italian coach, who took charge of Madrid for the first time in their 6-0 thrashing of Bournemouth, has had to fend off questions about the Portuguese star's future while the latest reports from Italy suggest that Napoli are close to securing Higuain.
Ronaldo, who has two years remaining on his deal, has been persistently linked with a move away from the capital-based outfit with Manchester United and Paris Saint-Germain the main contenders for his signature, but Ancelotti has denied that the Portuguese will be leaving anytime soon.
"Cristiano is the most important player in the team and he will be in the future, everyone knows him and he plays good games and is good for the club," he told reporters.
"Higuain is a fantastic player and right now is a Real Madrid player."
Madrid put on an exhibition display as they put six past Bournemouth, with Ronaldo grabbing a double while Sami Khedira, Higuain, Angel Di Maria and Casemiro all got on the scoresheet.
Ancelotti said he was pleased with the workout but there is still a lot more to come from his side.
"The most important thing is that the team worked hard and players like Cristiano Ronaldo, Ozil, other important players and youngsters played with flair in attack and performed well.
"We had problems at first but had some good moments; we controlled the match and played well. We have high calibre players with flair and I am very happy with the squad.
"The first match went well, our aim is to play good football, we have quality and we had a few good moments, some not so good but that is normal, it is the first match and I'm happy because the team worked hard.
"Naturally we have to improve but it is logical after one week of training,"
Ancelotti was also not afraid to try out different players in different roles with Ozil and new signing Isco forming a partnership in midfield.
He added: "It was an experiment, but I believe quality players can play together. It is important to find a balance between attack and defence, which is the most difficult thing.
"I think we need time for that and we will eventually get there."