Gareth Ainsworth sacked by QPR after home defeat to Leicester
Ainsworth - a former player for the Hoops - arrived at the London club from Wycombe Wanderers in February but has lost 10 of his 14 league games in charge so far this season.
QPR's CEO Lee Hoos said in a statement on the club's website: "Making a call such as this is never easy, and it is even more difficult when you have such respect on both a personal and professional level for the individuals concerned - which we all do for Gareth and Richard.
"Many supporters have told me in recent months that they have never wanted someone to succeed more than Gareth, which is an indication of the fondness everyone associated with QPR has for him.
"Unfortunately, results this season haven't gone the way we all wanted and we feel a change is necessary.
"Gareth has been a pleasure to work with from the moment he arrived and I am truly sorry this has not worked out as we all had hoped.
"On behalf of the board, I wholeheartedly thank Gareth for his commitment, desire, passion and professionalism. We all have the utmost respect for him, and he will always be welcome here.
"We understand the importance of appointing a new head coach quickly and an announcement on this will follow in the coming days."