United have been tracking the France Under-17 international for some time and they have finally managed to land the 16-year-old, who signs for an undisclosed fee from the former Ligue 1 champions.
The midfielder has already made his debut for the Red Devils' youth squad, having played in the 3-2 defeat to Wolves in the Under-18 Premier League Cup, and Under-18 coach Kieran McKenna is happy with the new arrival.
"He [Traore] is a boy we've been looking for a while. He is a really powerful midfielder who likes to run box to box," he told the club's official website. "He is a nice man and his English is improving. He's settling well with the other boys and has taken to the club really well."