Remy, who joined Rangers in January from Marseilles, was unable to save the London club from relegation but will get another chance to shine in the Premier league after making the move to the north-east.
"Remy signalled his intentions to the club earlier this summer of his desire to play in the top flight in a World Cup year, and following the recent addition of Charlie Austin to (our) ranks, a deal has now been agreed with Alan Pardew's side," QPR said in a statement.
"It will be a huge honour to play for such a big club," the 26-year-old Remy said on Newcastle's website.
"I was very flattered by the club's interest in me back in January and also very happy that they showed interest in me again this summer.
"I am very motivated this year to get into the World Cup squad for my country. I know in order to do that I need to have a big season and a successful campaign with Newcastle United."
Remy joins a sizeable French contingent at Newcastle, which also includes Yohan Cabaye, Hatem Ben Arfa and Yoan Gouffran.