The 26-year-old has been regularly linked with a move away from the Stadium of Light this summer and has now moved to west London.
He joins Shaun-Wright Phillips who also completed a move to west London on Wednesday, joining from Manchester City.
"I came down from London on Wednesday and spoke to the gaffer, and was impressed with his thoughts on where the club is going to go," Ferdinand told the club's official website, www.qpr.co.uk.
"I've heard good things about the manager and, after speaking with him, it's clear that he wants the best for me and wants me to do well.
"As soon as I came out of the meeting with him, I knew that QPR was the club for me."
Ferdinand has signed a three-year deal at Loftus Road for an undisclosed fee, following in the footsteps of second cousin and club legend Les Ferdinand.
"Anton's a player that I have always admired," said QPR boss Neil Warnock.
"He's got so much to offer. When you look at centre-halves in this country, you won't see much better than Anton on a good day.
"I'm going to try and give him more good days than bad! He's got to work very, very hard, but I see a lot in him. He's got a lot still to prove and hopefully he's with the right team to do that with."
Source: PA
Source: PA