QPR named Ramsey and Kevin Bond as caretaker bosses following Harry Redknapp's sudden resignation earlier this month.
And the 52-year-old, who earlier this week stated he would be interested in the role full time, has now been asked to lead the first team through to the end of the campaign.
"This is a great privilege and an honour for me. I am excited about leading the club between now and the end of the season," Ramsey told QPR's official website.
"I believe in this group of players, the staff, and everyone working at the club.
"I'd like to thank the QPR supporters for their support so far and with their backing, I am confident that we can build on Tuesday's win at Sunderland and start to climb the table.
"During this period, I will still be involved in the running of the Academy for the rest of this season and beyond. Continuity is very important when it comes to the development of young players, which is something I am very mindful of."
Chairman Tony Fernandes added: "In the wake of Harry Redknapp’s resignation, it was my desire to identify the right individual for the job and at this time, we believe Chris is the ideal candidate.
"He has impressed everyone here in his short time in charge and I firmly believe he is the right man - working closely with [director of football] Les [Ferdinand] - to lead us until the end of the season.
"Chris has an opportunity now to stamp his authority and class on the position. He is part of our long-term plans at QPR.
"A lot has been written and said about the position, including by myself, but the decision has been taken to defer the permanent appointment until the end of the season.
"We spoke to many individuals who were interested in the role, one of whom I was quoted on as being a dream, but none of them were right to take the club forward at this time for a variety of reasons, whereas we firmly believe Chris is."
Former Tottenham manager Tim Sherwood was the favourite to take the reins at Loftus Road, but reports suggest that move broke down over personal terms.
Michael Laudrup was also linked with the post, but the ex-Swansea manager - now in charge of Qatar side Lekhwiya - ruled himself out of contention.
Under Ramsey, QPR have lost and won one Premier League game, the London side beat Sunderland 2-0 on Tuesday for their first away points of the season.
That result left QPR 17th, outside of the relegation zone on goal difference.
