The former Arsenal trainee, whose 12 goals helped City win promotion to the Championship last season, will sign a three-year deal on July 1.
Emmanuel-Thomas is relegated Rangers’ third close-season signing following deals for Swindon midfielders Massimo Luongo and Ben Gladwin.
The 24-year-old told the QPR website: “This is a new chapter for me and I can’t wait to get started here. As soon as I spoke to Les Ferdinand and Chris Ramsey and they explained the way they want QPR to play, it was an easy decision for me.
“I’m here to come in and do a job and I’m confident I can keep improving as a player.”
Head coach Ramsey said: “I’ve always admired Jay from afar, and I’m really delighted we’ve reached an agreement to bring him here.
“There was a lot of hype surrounding him when he was a young player at Arsenal, and although he’s had a very steady career since then, this is now a real opportunity for him to really kick on at QPR.”
And director of football Ferdinand said: “He’s a young, hungry player with a great desire to keep improving and bettering himself. He can play in all the front positions, either as a 10, a main striker, or a wide player.”