The midfielder has penned a four-year contract at the club, six years after leaving Turin for Old Trafford.
The 29-year-old has been a free agent since leaving the Premier League club following the expiry of his contract, marking the second time he has left for nothing, while he takes the squad number made available by Paulo Dybala.
The forward is now a free agent himself after leaving upon the expiry of his contract.
Despite joining United for £89million in 2016, his time in Manchester didn't quite go to plan, but that doesn't mean that fans in Italy aren't delighted to get him back, leading to a hero's reception upon his arrival last week.
During his four years at the club between 2012 and 2016, Pogba scored 34 goals and created an additional 40 in 177 appearances.
It's that sort of record that has put him firmly among the club's greats.
In taking the number 10 jersey, Pogba reclaims the shirt worn in the 2015/16 season, and joins two of Juventus' biggest stars.
Among the names to wear the famous shirt are Roberto Baggio, Michel Platini and Alessandro Del Piero.
Baggio scored 115 goals in 200 appearances between 1991 and 1995, while Del Piero spent almost his whole career in Turin.
During that time he scored 289 goals in a staggering 702 appearances.
While Pogba has serious work to do to get anywhere near those names in terms of becoming a legendary figure in Turin, the hope for the 29-year-old will be that he can show the football world his undoubtedly quality on a more consistent basis than he did in Manchester.