The 26-year old French striker, who joined the R's from Marseille in January, will spend the 2013/14 Premier League season with the Magpies.
Remy, who netted six goals in 14 league outings for the relegated R's last term, was excited about embarking on a full top flight campaign.
"I'm very happy to be a Newcastle player. It will be a huge honour to play for such a big club," he said.
"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.
"The Premier League is the best league in the world and that's where I want to play.
"I am very motivated this year to get into the World Cup squad for my country and I know in order to do that I need to have a big season and a successful campaign with Newcastle United."