However, his side have made a disastrous start to the current campaign failing to win any of their opening seven matches.
A statement read: "QPR have terminated the employment of John Gregory as first-team manager with immediate effect, following Sunday's 5-1 defeat at West Bromwich Albion.
"First-team coach Mick Harford has been appointed caretaker manager to take the team to Wednesday's fixture against Colchester United."
Chairman Gianni Paladini added: "The club would like to thank John for everything he has done during a difficult period as manager, in particular for saving us from relegation last season.
"However, the performances and results this season have not met with our expectations. The league table does not lie.
"The club have decided to act swiftly in time to turn things around for the remainder of the season."