The 28-year-old had two years left on his previous deal, but the Magpies have moved to keep the winger at St James’ Park for an additional two years.
“I’ve said many times that I love playing for Newcastle. I love the city, the fans and the team,” he told the club’s official website.
“So I had no hesitation in signing a new contract. It has been a good start to the season and this is a great place to be.
“I am proud that the manager and the board see me as part of the long-term future of Newcastle. I have always given my best here and I will always do that.”
Toon boss Alan Pardew added: “Jonas is an integral part of the future of Newcastle United and we are delighted to have signed a new contract with him.
“As a seasoned international player, he adds a different dimension to our play when he is on the field and is a huge asset to us.
“Jonas can turn a game in an instant, he has marvellous ball skills, a terrific work rate and in my time here, has hardly missed a game.
“That’s the sort of consistency, fitness and performance wise, that a manager looks for in a player.”
