His former Real Madrid teammates Sergio Ramos and Toni Kroos wished Ronaldo the best of luck in his next chapter.
Ronaldo, 33, spent nine years with Real Madrid, becoming the club's all-time leading goal scorer and capturing four Champions League titles with the club during that time.
"Real Madrid has conquered my heart and that of my family, and that is why more than ever I want to say thanks: thanks to the club, to the president, to the directors, to my friends, to all the coaches, doctors, physios, incredible workers that make everything function that are attending tirelessly to every detail".
The 27-year-old, who has always been linked to Real Madrid, is now starring for Belgium at the World Cup in Russian Federation.
The Serie A champions swooped to sign the Portugal captain after he indicated that he was considering leaving Madrid after their Champions League final win in May.
Patrice Evra has urged Cristiano Ronaldo to snub a return to Manchester United and instead move to Juventus this summer.
History beckons as France take on Belgium
As for Belgium , their Golden Generation put in one of the best tactical performance of the World Cup to defeat Brazil 2-1. There is then the midfield contest between Pogba and Kevin De Bruyne , who plays for United's city rivals Manchester City.
Juventus have dominated Italian football for years, with the Serie A giants winning the league title in each of the last seven seasons and completing the domestic double in the four most recent campaigns.
These years at Real Madrid and in this city of Real Madrid have quite possibly be the happiest years of my life.
Juventus have yet to announce the transfer, though the five-time Ballon d'Or victor said his farewells to Madrid in a letter published on the LaLiga club's website.
"However, I believe that the time has come to start a new era in my life and that is why I have asked the club to allow me to move".
He is also a five-time world player of the year, a record he shares with his eternal rival, Argentine talisman Lionel Messi. Whatever happens, Madrid must replace the goals Ronaldo has scored so consistently. And with those, on an individual level, I also have the satisfaction of having won four Ballon d'Ors and three Golden Boots.
Cristiano scored an incredible 451 goals in 438 games, meaning an average of 1.03 goals per game played for Los Blancos.