QPR have completed the signing of Nedum Onuoha from Manchester City for an undisclosed fee on a four-and-a-half year contract.
It is believed that Onuoha has cost a fee in the region of £3 million.
New QPR manager Mark Hughes is desperate to bring in new players to help stave off relegation but failed to land Alex from Chelsea and Henrique Almeida from Sao Paulo.
The Alex deal broke down due to wage demands and Henrique was unable to obtain a work permit.
QPR thought to be in talks to sign Nancy midfielder Samba Diakite. The Mali international is one of several targets Hughes is looking to bring in during the final days of the transfer window. The Rs will have to fight off reported interest from Lyon to secure Diakite's signature.
Hughes told the club's official website: "Nedum is a player I know very well. He did very well for me at Manchester City and played a number of games, probably more than under any other manager.
"Nedum is very versatile. He can play centre-back or right-back, and has good pace. He is a very good addition to the squad. It's important that we are able to attract good players here. Nedum had other options but his experience with myself and the other guys here was a big factor in why he has come to us. I am pleased about that.''
Onuoha said: "This was the right time for me to join a club like QPR. The manager obviously played a massive factor in my decision to come here. I've worked with him before and he always wants players around him who are open and honest.
"He wouldn't have come here if he didn't believe that there was a squad of players here that can achieve the goals he has. The ambition of the owners was really appealing. This is my club now and I'll give everything to help us succeed.''
Onuoha could make his QPR debut in Saturday's FA Cup tie against Chelsea, although Hughes has previously indicated he is willing to give the versatile defender time to settle in due to his recent lack of first-team football.