The 28-year-old has signed a four-year contract with QPR that will keep him at Loftus Road until the summer of 2015.
Barton joins the club on a free transfer after being told he could leave the Magpies earlier this summer.
Barton said: “It’s been quite a whirlwind, so to get things finally sorted and draw a line under it all is a great relief.
“The ambition of the Club really impressed me. There’s obviously a great set of lads here already and that’s why they had such a great season in the Championship.
“The gaffer is talking about adding two or three more bodies and that, combined with the potential of the Club and the new owners’ ambitions, bodes really well for the future.”
“We’ve got a very, very good player on our hands,” he continued. “He’s coming here to show people what he can do. He wants to get back into the England team.
“He’s very enthusiastic. People will say one or two things about him, but they’ve said stuff about me in the past too, so I won’t worry about that.”
QPR boss Neil Warnock added: “He’s a winner. Even without the armband on, he’s a captain every week. He’s a lot better player than people give him credit for. Hopefully we can harness all his positive characteristics and get the best out of him.”