The 21-year-old has signed a five-month loan deal with the Bundesliga outfit as they look to bolster their attack for a European challenge.
Macheda, who has been at Old Trafford since he was 16, has been loaned out to QPR and Sampdoria previously and has struggled to gain first-team chances after returning to Manchester following these experiences.
“We wanted to sign a forward and are happy to have brought in Federico Macheda,” said Stuttgart sports director Fredi Bobic
“He is young, hungry and fits well with the VfB. He comes from a top club where he has shown what he can do. Now we want to integrate him into the team as quickly as possible.”
Macheda made his name after scoring a crucial stoppage time winner against Aston Villa in 2009 and struck late in the next game against Sunderland, helping the Red Devils to win the title that campaign.
Since then he has played less than 20 games for United and looks set for a career away from Old Trafford.
“I have followed the Bundesliga and of course I know Stuttgart,” said Macheda on his new club’s official website.
“I’m delighted to be able to play for them now. I now have got to get to know my team-mates and settle in, because we have got many interesting games in three competitions to come.”