The 37-year-old keeper signs from Birmingham City after missing just two league matches and has a plethora of experience under his belt with his most famous spell being at Norwich in which he made over 200 appearances.
Speaking to Newcastle’s club website he stated: "This is a massive club and it's a massive opportunity, so I'm really excited to get started.
It was an opportunity I couldn't turn down. It's a huge, huge club which is only going one way and to be a part of that, however big or small, is going to be very pleasing and very exciting.”
Manager Eddie Howe also told the website: “I'm pleased to welcome John to Newcastle United. He has a huge amount of experience and adds a level of support and competition that we need.
As well as his abilities on the pitch, he has a strong mentality and he is a leader, which will only benefit the group. I'm looking forward to him joining us as we prepare for the season ahead."
With Newcastle fully stocked with goalkeeper options it could lead to the departure of Martin Dubravka.