The Republic of Ireland international joins Harry Redknapp's side as the Londoners look to boost their striking options in their push for promotion to the Premier League.
Doyle has made 23 League One appearances for Wolves this season, but after the arrival of Leon Clarke he has been allowed to make the move to Loftus Road as a direct replacement for the injured Charlie Austin.
The 30-year-old will be eligible to make his debut in Saturday's clash with promotion rival Burnley.
The Republic of Ireland international has only three goals in England's third tier this season, but remains confident he can help the club's push for the Premier League.
"It was all agreed pretty quickly," he told QPR's official website. "I jumped at the chance to come here to be honest. The club's in a great position for a tilt at promotion and I can't wait to be part of it.
"It was a massive draw to know I'll be part of a promotion push and obviously the manager played a huge role in my decision to come here as well."
Manager Harry Redknapp was delighted to have completed the deal for Doyle and hopes he can make an immediate impact.
"I like Kevin, he's a good pro and a good lad who needs to get his career up and running again," he said. "This is a great opportunity for him. He'll be a key addition to the squad."