Lucas Hernandez won a treble with Bayern Munich in his first season at the German club
A 2018 World Cup winner with France, Hernandez won a treble with Bayern in 2019-20 - his first season at the club.
After winning the domestic league and cup double, Hernandez helped Hansi Flick's team defeat PSG to win the Champions League.
Hernandez, who played 107 times for the Bundesliga champions and scored twice, has signed a five-year deal.
"I'm really excited," Hernandez said. "I've been waiting to join PSG for a long time, and it's finally happened. It's a very special day for me and I'm very happy to be here."
He played a key role in France's 2018 World Cup win in Russia but, despite being selected for Les Bleus in the 2022 World Cup in Qatar, a knee injury sustained in their third group game - the 4-1 win over against Australia - ruled him out for the remainder of the tournament.
They reached the final for a second consecutive tournament, but were defeated by Argentina on penalties.
His younger brother, Theo Hernandez, plays for AC Milan in Serie A.
-- Courtesy of BBC Sport