"Paris Saint-Germain is delighted to announce that Renato Sanches has signed a five-year contract with the reigning French champions. The Portugal midfielder is now tied to the club from the French capital until 30 June 2027," PSG said in a statement.
The 24-year-old Benfica product was part of the team that won the Portuguese league title in 2016.
He was transferred to Bayern Munich later that year where he won four consecutive German Bundesliga titles.
The central midfielder had a loan spell with Swansea City in England during the 2017-18 season.
He scored six goals and had 10 assists in 90 matches for Lille.
Sanches won the UEFA EURO 2016 title with the Portuguese national team.
He has amassed 32 international caps for Portugal.