The Argentina international, who played in Serie A for Palermo before joining PSG in 2011, returns to Italy on a five-year deal after completing a €24.7million (£21.8m) move.
Pastore boosts Roma’s midfield on the same day Radja Nainggolan left to join Inter Milan in a deal which saw Davide Santon and Nicolo Zaniolo move to the Giallorossi.
“I’m very happy to have arrived in Rome, it’s nice to come back to Italy and do it in a great team,” Pastore, who at one point appeared close to signing for Premier League club West Ham, told his new club’s website.
Club sporting director Monchi added: “The arrival of Pastore makes me happy, because we are talking about a player who can excite the fans with his games.
“In my career as a sports director I have taken so many players, Javier is probably the one with the most quality.”
Pastore: “I am very happy to be here at #ASRoma. It is great to return to Italy, and to do it with such a great club.
“I hope to repay in full all the enthusiasm, support and affection that Roma fans have shown me already.” pic.twitter.com/x3qqdymLQU
— AS Roma English (@ASRomaEN) June 26, 2018
