The England international will link-up with former boss Mark Hughes at Loftus Road and becomes the R's second signing of the day following the purchase of Djibril Cisse from Lazio.
Zamora told the club's official website: "QPR are certainly a club that are looking to go forward. That's something that I'm looking forward to being a part of.
"I got on really well with the Manager at Fulham. We all grew to like Mark. I think that will be the case here. He's looking to take the Club forward.
"I think this was the right time for me to have a fresh challenge. I had some great experiences at Fulham. Going to a European final is special. But this is a new challenge for myself and I'm thoroughly looking forward to it."
The 32-year-old believes that Rangers can haul themselves away from the relegation zone and push forward up the Premier League table.
He added: "The ambition of the club was certainly a drawing factor as well.
"I've been lucky enough to speak to Tony [Fernandes] and Phil's [Beard] relayed a lot of messages about where this club want to go. For me, it was quite an easy decision to be a part of this.
"The sky's the limit. We're looking to go forward and to grow and I want to be a part of that."
Hughes is equally delighted to have captured a player of Zamora's calibre and is eagerly anticipating seeing the striker in action for the club.He said: "Bobby is a guy that makes things happen on the pitch, be it scoring goals or creating chances for others. He's a great foil for any team.
"We needed a player of his ilk at the football club and I couldn't be more delighted."