The 67-year-old has been at the west London club for just over two years and although he could not prevent them suffering relegation in the 2012-13 season, he went on to lead them to playoff victory the following season.
However, the Rs sit 19th in the Premier League after 23 games and have suffered 11 consecutive away top-flight losses this season, and with the club failing to secure any signings on deadline day, the club's official website broke the news of Redknapp's resignation.
A statement from Tony Fernandes read: “I would like to take this opportunity to thank Harry for everything he has done for QPR during his time in charge.
“We part on good terms and I would personally like to wish him all the best for the future.”
Redknapp added: “I have had such a fantastic time at QPR. I would like to thank the Board, the players and all my staff, and especially the supporters who have been absolutely fantastic to me since I arrived at the club for their tremendous support.
“Sadly, I need immediate surgery on my knee which is going to stop me from doing my job in the coming weeks. It means I won’t be able to be out on the training pitch every day, and if I can’t give 100 per cent, I feel it’s better for someone else to take over the reins.
“My relationship with Tony Fernandes has been one of the highlights of my footballing career and I wish the club every success. I am confident they will survive in the Premier League this year.”
Chris Ramsey and Les Ferdinand have assumed temporary control of the first team until a successor is named.
