Hatem Ben Arfa became Newcastle boss Alan Pardew's first signing on Wednesday after his season-long loan move became permanent.
The 23-year-old Frenchman has signed a four-and-a-half-year deal after the Magpies agreed an undisclosed fee with Marseille.
Ben Arfa has been out of action since suffering a double leg fracture in a challenge with Manchester City midfielder Nigel de Jong in October, but showed enough in his four appearances for the club before that to persuade them of his ability.
He said: "I am absolutely delighted to be signing for Newcastle United on a permanent basis.
"During my short time at the club, I thoroughly enjoyed playing for the team and for the supporters too. This is a great club and I am very happy to be committing my future to them.
"I am getting back to fitness as quickly as I can and am really looking forward to getting back to St James' Park, seeing the lads again and working with Alan Pardew and his staff.
"During my time out, I have been inundated with messages of support from fans and I want to repay them all with good performances on the pitch later this season."
Pardew, who has moved quickly to tie up a man initially recruited by predecessor Chris Hughton amid reported interest from other parties, was delighted to have made an early breakthrough as he targets offensive reinforcements.
The manager said: "When I came to the club last month, one of my priorities was to secure Hatem on a permanent deal.
"The last thing I wanted was for us to lose him when his loan ended, so we are really pleased to have agreed that deal today."