The 25-year-old has been little more than a fringe player at City and now looks set to link up with former manager Mark Hughes at Loftus Road.
Onuoha is driving down from the north-west to have a medical on Wednesday night or Thursday and it is understood the move is fairly close to completion.
QPR were given permission to speak to the defender last week after agreeing a fee understood to be ?2.5million.
There have been reports of the fee being as high as ?4million and wages of up to ?80,000 per week, but it is understood that Onuoha would earn significantly less than reported.
The former Sunderland loanee will be looking to get his season back on track should he complete the move to west London, having made just three appearances this season.
Hughes knows Onuoha well from his time at the City helm and, speaking last week, said he would give him time build up his fitness.
"The lack of playing time would be factored in," Hughes said. "We would be mindful of that. We have to understand he has not had a lot of game time but he is a player I know and as an individual as well.
"I am sure he will be very keen to make an impression very quickly."
Should Onuoha sign, he would become QPR's third signing of the January transfer window - and second of Hughes' reign - following loan deals for Manchester United striker Federico Macheda and AC Milan's Taye Taiwo.
Source: PA
Source: PA