Neither club have revealed the price final tag for Cabaye - with Newcastle announcing the sale for "an undisclosed fee" on their website - but reports in France on Wednesday suggest PSG have paid in the region of £20million.
Club president Nasser Al Khelaifi said: "I am very happy to give a player with Yohan's talent the chance to return to France."
PSG's recruitment since the investment of Al Khelaifi's Qatari consortium has been cosmopolitan, with Cabaye linking up with the likes of Sweden's Zlatan Ibrahimovic, Uruguay striker Edinson Cavani and Brazilian Thiago Silva.
And Al Khelaifi said: "I have said before, PSG will try to bring in French players. That is very important for us but it was not the reason for signing Yohan. The first reason is his talent.
"I hope, and I am very confident, that Yohan will be very strong for us in the league and the Champions League."
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