QPR endured a sixth successive league defeat when beaten 2-1 at home by the Championship leaders Leicester on Saturday to sit second bottom, which led to Ainsworth’s departure.
The appointment of Cifuentes is subject to a work permit and will prompt him leaving the Swedish top-flight side Hammarby, where the 41-year-old Spaniard has been for the past two seasons.
Lee Hoos, the QPR chief executive, said on the club website: “We are delighted to bring Martí in and I would firstly like to thank Hammarby for being fantastic to deal with throughout the process.
“Martí is an exciting appointment and we look forward to seeing the impact he can have. Having a succession plan in place is a necessary part of football, irrespective of how the team are performing. Martí is someone we have been aware of so we are really pleased to have been able to secure his services.”
QPR had previously been linked with appointing Neil Warnock as manager after Ainsworth’s exit.
