The 63-year-old was dismissed from the Loftus Road club after nearly two years in charge.
During that time Warnock guided the side to promotion to the Premier League.
However, a string of poor results have left the R's 17th in the Premier League table.
"Obviously I'm very disappointed, but having achieved so much, I leave the club with a great sense of pride," he said in a joint statement.
"I have enjoyed my time here more than anywhere else and the QPR fans have been brilliant with me - they deserve success.
"I've been involved in the game a long time and I will be spending the immediate future with my family and friends before deciding my next career move."
Mark Hughes has been tipped as the early favourite to succeed Warnock at Loftus Road.
Click here for the full statement released by Queens Park Rangers.