The Ivorian, who is set to depart for the Africa Cup of Nations with Ivory Coast following the New Year's Day fixture, came off the bench to net the leveller at the end of a match in which Swansea rarely threatened.
Leroy Fer gave QPR the lead with a thunderous strike in the 20th minute after Rob Green had escaped punishment for a handball outside the penalty area.
The visitors had Wayne Routledge controversially sent off for his reaction to a heavy Karl Henry challenge in the closing stages, but there was still time for Bony - a 71st-minute replacement for Gylfi Sigurdsson - to have the final word.
Swansea's record signing received the ball in the box from Ki Sung-yueng - also jetting off to the Asian Cup after the match - and turned before firing beyond Green in the QPR goal to snatch a point.
Despite throwing away the lead, QPR are now unbeaten in six matches on home soil, while Swansea will be thankful to have escaped with a point.
Harry Redknapp brought Eduardo Vargas in for Junior Hoilett on the right wing, while Garry Monk elected to leave top scorer Bony on the bench as he made three changes.
But it was Swansea who had the first clear-cut chance to open the scoring in the seventh minute.
Running onto a Sigurdsson throughball, Routledge tried to round Green, who had raced out of his box to meet the advancing winger - only for the goalkeeper to knock the ball out of his path with his left arm just outside the area.
The handball went unnoticed by the officials, however, and there were few appeals from the visiting players.
Charlie Austin found himself in acres of space in the centre of the penalty area from a corner after 18 minutes, but was unable to punish the lax Swansea defending and turn the ball into the net.
Monk's men were less fortunate after their next defensive lapse, though.
Federico Fernandez's headed clearance fell at the feet of Fer, who took two touches before rifling in an unstoppable effort from 20 yards.
Mauricio Isla forced goalkeeper Lukasz Fabianski into a diving save from 15 yards before the interval and Austin headed against the base of the right-hand post after the players re-emerged.
Swansea's last visit to Loftus Road produced a 5-0 victory on the opening day of the 2012-13 season, but the Welsh club struggled to find a way past this term's most porous defence on Thursday.
Fernandez and Sigurdsson both saw efforts go just wide, before Monk decided to bring Bony – heavily linked with a move away from the Liberty Stadium this week – on for the last 20 minutes.
The Swansea boss might have been rueing his decision to bring off free-kick specialist Sigurdsson for Bony when Ki was brought down just outside the box, but the Ivorian striker drew an excellent diving save from Green.
Routledge's red card four minutes from the 90 looked to have boosted QPR's chances of holding out for maximum points, but Bony fired home two minutes into stoppage time to earn his side a point.
Swansea did, however, have to be alert in their own penalty area as the home side piled on the pressure in the dying seconds.
