The club announced on Friday that it had reached an agreement with Juventus to re-sign the 36-year-old Portugal star for a reported £12.8m.
After the news was announced just after 5pm, Twitter and Instagram went into a frenzy, with the post receiving more than one million likes on the former and nearly 7 million on the latter within the space of an hour.
Welcome 𝗵𝗼𝗺𝗲, @Cristiano 🔴
#MUFC | #Ronaldo
— Manchester United (@Manchester United)
In one humorous clip that has gone viral, supporters in the background of a news story appear to be literally jumping for delight at the news.
Before leaving for Real Madrid in 2009, Ronaldo scored 118 goals in 292 games during his first time at Old Trafford.
United made its announcement following a frantic 24-hour period. Manchester City appeared to be one of the frontrunners to sign the former Real Madrid player, with some rumours claiming the two had already agreed on personal terms.
But Ronaldo has chosen to return to United, where he spent six years under Sir Alex Ferguson and won three Premier League crowns, one Champions League, two League Cups, and one FA Cup, as well as the Fifa Club World Cup and Community Shield.
In the beginning, Ronaldo believed there was no prospect of a reunion with his previous club, but United has opted to pursue it, while City has lost another striker option after major target Harry Kane agreed to join Tottenham.
Juventus told Ronaldo on Wednesday that they were open to trade him during the transfer window provided that interested teams met their terms.
“[Ronaldo] gave his contribution, he made himself available, now he leaves and life goes on," Juventus manager Massimiliano Allegri said on Friday. He is to be thanked for what he has done, also as an example among the youngsters. But as I said, we must go on,” he continued.