Messi left Barca – the only club he has played for – as they were unable to afford a new deal under Spanish League’s financial fair play rules.
“I am impatient to start a new chapter of my career in Paris. The club and its vision are in perfect harmony with my ambitions,” said the Argentina star.
“I know how talented the players and staff are here. I am determined to build, alongside them, something great for the club and for the fans. I can’t wait to set foot on the Parc des Princes pitch.”
Considered one of the greatest players of all time, Messi scored a record 672 goals in 778 games for Barca, the club he joined as a 13-year-old.
The striker has won the Ballon d’Or a record six times and lifted 35 trophies with the Catalan club.
Messi could make his PSG debut at home to Strasbourg on Saturday. (BBC)