The 28-year-old midfielder has swapped Tyneside for the French capital after the Ligue 1 champions agreed a deal with the St James' Park outfit on Wednesday
The midfielder has signed a three-and-a-half-year deal with the capital club and will wear the No.4 shirt.
"I was won over by the ambitious project at Paris Saint Germain and I can't wait to join this exceptional squad and help the team reach its objectives in France and in Europe," he told PSG's official website.
Meanwhile, president Nasser Al-Khelaifi also revealed his delight at being able to bring the France international to PSG.
"Wanted by a number of prestigious clubs, the new Parisian midfielder has chosen to join Paris Saint-Germain," he said.
"The transfer of Yohan Cabaye is further proof of the club's ability to attract the best French and overseas players.
"We are especially delighted to welcome him to the Paris Saint-Germain family to help in its upcoming challenges in the second half of the season."
Cabaye joined Newcastle from Lille for €5.2m in 2011, scoring 17 Premier League goals in 79 appearances - including a superb double against West Ham in what will now be his last ever appearances for the club.