The Premier League giant said an agreement had been reached with Juventus for the 36-year-old, who scored 118 goals in 292 games during his first spell at Old Trafford.
“Everyone at the club looks forward to welcoming Cristiano back to Manchester,” read a short statement from the club.
The five-time Ballon d’Or winner enjoyed six successful years at Manchester United, winning three league titles and one Champions League, before joining Real Madrid in 2009 for a then world record fee.
He is now set to reunite with former teammate Ole Gunnar Solskjaer, who praised Ronaldo earlier on Friday prior to the agreement.
“Cristiano has been a legend of this club, he is a legend of this club, he’s the greatest player of all time, if you ask me,” the United manager said during a news conference.
Earlier on Friday, Juventus manager Massimiliano Allegri said Ronaldo would not play for the Italian club after saying he wanted to leave.
Reports had linked Ronaldo with a move to United’s fierce rivals Manchester City but a deal never materialized.
Ronaldo won the Serie A title in his first two seasons with the Old Lady but was unable to lead the Italian club to the Champions League title — a competition he won four times with Real Madrid.
Juventus finished fourth last season and speculation over Ronaldo’s future had been swirling ever since with less than 12 months left on his contract.
More to follow…