The jersey was previously donned by Edison Cavani but the Uruguay international has reluctantly given the jersey back to Ronaldo. The former Paris Saint-Germain man will now wear the no. 21 jersey.
Ronaldo inherited the iconic jersey from David Beckham and created history with it in Manchester between 2003 and 2009, before leaving for Real Madrid.
A statement on the club's website read: “Manchester United can confirm that Cristiano Ronaldo will wear the iconic no.7 shirt after returning to Old Trafford.
“The Portuguese superstar famously wore the legendary shirt number during his first spell at United and we can now confirm that Ronaldo will have it on his back once again.
“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.
“As we all know, the no. 7 is a special number in the history of United.
“It has previously been worn by club icons 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 in our away win at Wolverhampton Wanderers last weekend.
“As our new signing is allocated no.7, El Matador will switch to no.21, the same number our prolific striker wears for the Uruguayan national team.
“United’s first fixture after the international break, in which Ronaldo could make his return to Old Trafford, is at home to Newcastle United on Saturday 11 September.
“We are all excited to see our returning no. 7 in action at the Theatre of Dreams once again.”
Ronaldo will be expected to make his second debut for the Red Devils after the international break when Ole Gunnar Solskjaer’s side meet Newcastle United in the Premier League.
