The 40-year-old 2006 World Cup victor joins the big-spending Parisian side days after his contract with Juventus ended in June.
"His arrival reaffirms our will to always go higher, an ambition that we intend to pursue with a determination just as strong".
Winning the UEFA Champions League title with PSG would be a great career milestone for Buffon, as he has reached the final in 2003, 2015, and 2017 but never won.
According to French newspaper La Parisien, Buffon will arrive in Paris on Friday for a medical, and all being well will be presented as a PSG player on Monday.
Matuidi left PSG for Juve a year ago.
"I'm 40, healthy, so I will do my best to be important for PSG and to help my team-mates, not only the goalkeepers". "But when the season begins you can't think of enveloping all this in the aim for the Champions League because that would be complete craziness and we're not insane here".
The veteran stopper has joined the French champions on a one-year deal with the option of a second season at the Parc des Princes. "They have some extraordinarily talented players and an extraordinary coach".
"I've come to an ambitious club, where everyone wants to win". I spent 10 years at Parma and 17 at Juventus and created a comfort zone and that doesn't motivate me. "In one month, I will know more about the squad, and I will improve - I was unable to refuse that".
"I prefer to play on as long as my body allows me to", he continued.
Buffon remains as PSG's only new signing so far this summer.
In theory, Buffon will mentor Areola during his potential two-year stay in Paris, but he recognised that he has been an undisputed starter wherever he has played.
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