"We think he will add flair to the squad and we're confident he will fit in well with the team we have put together here," Newcastle manager Chris Hughton told the club's website.
The 23-year-old attacking midfielder had been linked with several clubs around Europe after becoming involved in a tense stand-off with Marseille, missing close-season training sessions as he sought an exit from the Ligue 1 side.
Marseille had kept hold of him after their Senegalese striker Mamadou Niang, last season's top scorer in Ligue 1 with 18 goals, left for Turkish side Fenerbahce but they have since signed forwards Loic Remy and Andre-Pierre Gignac.
"It was always my first choice to come here and I'm delighted to be here," Ben Arfa told the Newcastle website.
"All I'm waiting for is to show what I can do in front of the public in Newcastle. A lot of my friends in France already know the fans' reputation."
However, he was left out of the squad for both the 2008 European championships and this year's World Cup in South Africa.
