Wijnaldum opted not to sign an extension to his contract with Liverpool at the end of the season.
It was anticipated the 30-year-old was going to join Barcelona when his Reds deal expires at the end of June.
However, PSG, who finished second in Ligue 1 last season, are understood to have stepped in with a better offer and Wijnaldum has opted to join them.
The presence of Mauricio Pochettino at PSG is also thought to have been a factor.
Wijnaldum spoke highly of Pochettino before he joined Liverpool and although the deal is not completed, it is now anticipated the Dutchman will move to the French capital.
Wijnaldum, who is part of the Netherlands squad for Euro 2020, made 237 appearances for Liverpool, where he won the Premier League and Champions League.