The 31-year-old spent seven years at Manchester United following his arrival from PSV Eindhoven in 2005 and enjoyed numerous highlights during a trophy-laden Reds career.
Park, who played 205 times for United, will play his football this season alongside a couple of familiar faces. Fabio da Silva is already at Loftus Road on a season-long loan, while the Hoops are managed by Reds legend Mark Hughes.
Sir Alex Ferguson described Ji as "the ultimate professional" and will no doubt be wary of Park's presence when QPR visit Old Trafford in late November.
“He's been a fantastic servant to the club over the past seven years," the manager told ManUtd.com. "He is the ultimate professional and such a nice lad; he never let us down on the big occasions. Unfortunately, I just couldn’t give him the number of games he wanted.
"Everyone at Manchester United wishes him well for the future and I am sure he will be a great success at QPR.”
Always a fans' favourite, Park's tireless devotion to the cause and ability to rise to the occasion should ensure his enduring popularity among United fans. A true "big-game player", the Korean tended to reserve his greatest performances for matches against the likes of Arsenal, Chelsea and Liverpool and famously shackled Euro 2012 star Andrea Pirlo when AC Milan came to town in 2010.