GOAL - James Westwood
The 18-year-old centre-back has put pen to paper on a four-year contract which will see him remain at Allianz Arena until 2024.
Kouassi expressed his delight after being officially unveiled at Bayern on Wednesday, while promising to fight for a regular spot in the first team.
He said: “I’m really happy to be able to play for Bayern. It’s a great club full of tradition.
"I really hope to break through here and make a lot of appearances. I’ll work hard for that.”
Bayern sporting director Hasan Salihamidzic added: “We’re very happy to bring Tanguy Kouassi to Bayern. In our eyes, he’s one of the greatest prospects in Europe.
"His best position is at centre-back but he can play in a number of positions.
"We’re sure he’ll have a great career with us and is a real reinforcement.”
The France U-18 international opted against signing his first professional contract with PSG, despite having featured in 13 games for the club in the 2019-20 season.
Goal reported that Kouassi reached a final decision over his future on June 14 after months of negotiations with officials at Parc des Princes.
The teenage defender, who is also capable of operating in a deep-lying midfield role, has been linked with a number of top clubs across Europe this year.
Barcelona and Milan were reportedly among those considering a swoop, but Bayern ultimately convinced the Frenchman that he would be best served continuing his development in Germany.
Kouassi leaves PSG as a Ligue 1 title winner after the club were awarded the trophy for a third-successive year following the cancellation of the domestic campaign in April.
His most notable contribution came during in a 4-4 draw with Amiens back in February, as he notched his first two goals for Thomas Tuchel's side.
Kouassi will join up with a number of fellow countrymen at Bayern, who already have Benjamin Pavard, Lucas Hernandez, Corentin Tolisso and Michael Cuisance on their books.