PSG said in a statement that the 34-year-old Argentina star signed a two-year deal with the option for a third season.
“I am excited to begin a new chapter of my career at Paris Saint-Germain,” Messi said.
“Everything about the club matches my football ambitions. I know how talented the squad and the coaching staff are here. I am determined to help build something special for the club and the fans, and I am looking forward to stepping out onto the pitch at the Parc des Princes.”
No salary details were given but Messi is set to earn approximately 35 million euros ($41m) net, according to the Associated Press news agency, who spoke to a person with knowledge of the negotiations on condition of anonymity before the contract was signed.
“I am delighted that Lionel Messi has chosen to join Paris Saint-Germain and we are proud to welcome him and his family to Paris,” PSG chairman Nasser Al-Khelaifi said.
“He has made no secret of his desire to continue competing at the very highest level and winning trophies, and naturally our ambition as a club is to do the same.”
Messi will wear the number 30, as revealed in a video by the club, the number he had when he began his professional career at Barcelona between 2004-2006.