PSG will pay 45 million euros for him, with the potential addition of five million euros in bonuses.
"I'm really happy and proud to be joining such a great club," Barcola, a product of Lyon's academy, told the club website.
"It's a club with a lot of ambition, that plays in major competitions and I'm going to give it my all."
Barcola was promoted to Lyon's first team in 2021 and made 47 appearances across all competitions, 23 in the second half of the successful 2022-23 season during which he scored seven goals and provided 10 assists.
Barcola joined a list of notable arrivals at the Paris-based club, including midfielder Marco Asensio (27) from Real Madrid, forward Ousmane Dembele (26) from Barcelona and defender Lucas Hernandez (27) from Bayern Munich.
