He added that the Frenchman has the ability to bring a sense of “calm” to the club, and insisted the Frenchman is key to Real Madrid’s hopes this season.
Ronaldo, who scored a total of 51 goals in all competitions last season, lauded Zidane’s impact since he took over.
He said, “Zidane was the key to our season.”
“He came, made us work hard, work well. He’s a great professional and a great person.
“In my opinion, his best quality is his ability to give players a sense of calm.
“What coach can win the Champions League in six months?
“Zidane deserves much credit and I am very happy he is with us.”
Ronaldo led Portugal to Euro 2016 glory in the summer and hopes that form will continue now he is back with Real.
“Playing for the best club in the world, Real Madrid, the goal is always to win titles,” Ronaldo said.
“Obviously, the Champions League is the trophy that means more for Real Madrid, who have won it more than anyone else and it is always a major competition.
“It is special for me and for Madrid, so we will try to win it again this year.”