The no.7 is a special shirt in the history of United.
It has previously been worn by club legends like George Best, Bryan Robson, Eric Cantona and David Beckham. Now, it returns to the man who succeeded Beckham in it, Ronaldo.
Ronaldo inherits the number from Edinson Cavani, who wore the shirt last season and most recently in the away win at Wolverhampton Wanderers last weekend. It is the first time in Premier League history that special dispensation has been granted for a number swap.
Cavani will switch to no.21, the same number he wears for the Uruguayan national team.
Ronaldo wore the legendary shirt number during his first spell with the club.
In his first six seasons at the club, between 2003 and 2009, Ronaldo made 292 appearances and scored 118 goals, winning nine trophies including three Premier League titles and the UEFA Champions League.
If you are planning on buying a Ronaldo 7 jersey, KitBag.com has them for order.