The five-time Ballon d'Or victor confirmed the move to Serie A on Tuesday, ending a nine-year stay in Madrid which featured four Champions League titles in the past five years.
The 33-year-old will sign a four-year deal, taking him to when he is 37.
Ronaldo, who originally wore the No 9 shirt at Real Madrid before taking the No 7 following Raul's departure in 2010, would have demanded the shirt number to continue his CR7 brand. "My only feeling is of an enormous gratitude for this club, for these fans and for this city". I can only thank all of them for the love and affection I have received.
Ronaldo's astonishing £100m transfer from Real Madrid to Juventus will lead to a £10.6m payday for his agent, the Serie A club have confirmed.
Being the all time leading goalscorer for Real Madrid by scoring 311 goals in 292 matches, Ronaldo played an influential part in Real Madrid's 3 successive Champions League titles. Ronaldo, along with several other top players in the country, has been accused of tax fraud, with authorities saying the government was defrauded of €14.7 million ($17 million) from 2011-14.
Andrea Agnelli, the chairman of Juventus, flew out to Greece personally in order to meet Ronaldo and finalise the historic deal. Portugal made the last 16 of the tournament, in stark contrast to Italy, who failed to qualify for the first time since 1958.
Having single-handedly won the Euro 2016 for Portugal, Ronaldo was in scintillating form at the 2018 FIFA World Cup and scored 4 goals.