The France international scored six goals in 14 appearances for the Loftus Road side last term, after moving to England for €9.3 million from Marseille at the turn of the year.
Remy is delighted with the switch to St James' Park, having been keen to carry on plying his trade in the Premier League following QPR's relegation to the Championship.
"It will be a huge honour to play for such a big club," he told the club's official 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.
"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. I know in order to do that I need to have a big season and a successful campaign with Newcastle United.
"I am focussed on helping the team achieve success this season and scoring as many goals as I can."
Newly appointed director of football Joe Kinnear is pleased to have added more firepower to the squad ahead of the 2013-14 campaign.
"The need for us to strengthen up front was a priority and I have been working very hard to secure one of our targets in this position," Kinnear said.
"I'm delighted to have secured Loic for the season. Now we have him I'm sure he'll be a huge success for us; I know he's hungry for goals and is absolutely committed to helping us achieve success this season."