Sports Correspondent David Chisnall speaks to Sean Bones of Manchester United Supporters' Trust.
The 36-year-old is set to return to Old Trafford 12 years after leaving for Real Madrid.
The club said the deal was subject to the agreement of personal terms, visa and a medical.
A statement from the club said: "Everyone at the club looks forward to welcoming Cristiano back to Manchester."
Cristiano is a five-time Ballon d’Or winner and has won over 30 major trophies during his career.
Ronaldo scored 118 goals during six seasons at United, between 2003 and 2009, helping the club win three Premier League titles, a Champions League, the FIFA Club World Cup, two League Cups and one FA Cup.
Ronaldo had been heavily linked with a move to rivals and United's neighbours Manchester City.
City were offered the 36-year-old, who had made it clear he wants to leave Juventus, and were considered front-runners for his signature but decided the deal was not one they wished to pursue.
Reacting to the news, Manchester United and England plater Marcus Rashford Tweeted: "Wow wow wow, he’s home."
Manchester United fans react to the new of Ronaldo's return to Old Trafford.