Ronaldo wrote an open thank you letter to Real Madrid supporters that was published on the club's website. "I feel that it is time, and I ask everyone, especially our fans, to please understand me".
"Real Madrid announces that it has agreed to transfer Cristiano Ronaldo to Juventus FC due to the will and desire expressed by the player", the Madrid-based club said in a statement.
With Cristiano Ronaldo's future at the club looking increasingly perilous, the hierarchy at Los Blancos are busy drawing up a list of potential replacements for next season.
The 33-year-old would be a massive signing for Juventus, as Max Allegri looks to claim a Champions League trophy that has so far alluded him in his career.
Chelsea forward Eden Hazard has recently been the subject of intense transfer speculation linking him to Real Madrid.
Ronaldo left Manchester United to join Real Madrid in 2009, and won four C.L titles with the Spanish giants.
Chelsea star Eden Hazard has reportedly emerged as a summer transfer target for Spanish champions Barcelona who are said to be ready for a deal to sign the Belgium worldwide.
"I'm fine at Chelsea and, for now, nobody has presented me with an offer".
The signing broke the Serie A record, which Juventus set two years ago when it paid Napoli 90 million euros (then $99 million) for Gonzalo Higuain.
Since he made his Champions League debut in October 2003, Ronaldo has scored the most goals (120) and also has the most assists (36).
He spent six seasons in England, winning three Premier League titles, one Champions League title and one FA Cup. During these nine exciting years, I have had great players in front of me.
Ronaldo also became only the fourth player to score in four World Cups when he started this year's campaign with a hat-trick against Spain that culminated in a stunning free kick. Whatever happens, Madrid must replace the goals Ronaldo has scored so consistently.