Andrea Agnelli, the Juve chairman, was at Ronaldo's hotel in Greece on Tuesday as discussions over the move advanced, Ronaldo's agent - Jorge Mendes - was believed to be simultaneously meeting with Real Madrid.
There was little left for Ronaldo, Real's all-time record goalscorer with 451, to prove in Madrid.
Juventus announced that Ronaldo has signed a four-year, $382 million contract until the end of June 2022, and that the transfer is valued at $117 million which will be paid over two years.
"Cristiano Ronaldo? Any player would like to play next to him, it would be great", he said at a press conference.
"Beyond the conquered titles, the trophies and the triumphs achieved in the playing fields during these nine years, Cristiano Ronaldo has been an example of dedication, work, responsibility, talent and improvement".
That's because he and the rest of the Real Madrid team were offered their pick of club partner Audi's lineup last November and Ronaldo chose an 605 hp Audi RS7 for his one-year loan.
In a letter posted on Real Madrid's website, the multiple Ballon d'Or victor said his time in Madrid had been one of the happiest in his life.
After nine years at the Bernabeu, the Portuguese superstar is Italy-bound, as he will join the seven-time defending Serie A champions. Real Madrid confirmed the news in a short statement on their website earlier today.
Six years, three Premier League titles and a Champions League later and he was on his way to Real Madrid, having joined George Best and Eric Cantona among the greatest players to wear United's prized number 7 shirt.
He helped Madrid to La Decima in the Champions League final with Atletico Madrid in 2014 and played a crucial role in Los Blancos winning the competition in each of the last three seasons.
Ronaldo led Portugal to its first major title at the European Championship two years ago in France. Ronaldo scored four goals to take his tally to 85 for his country and break Ferenc Puskas' record as Europe's all-time leading worldwide scorer.