Boss Harry Redknapp said the England midfielder, who has made just four starts and four substitute appearances since joining the R's in 2011, was not involved in his future plans and no longer required at Loftus Road.
Speaking to the club's official website following the decision which takes immediate effect, Redknapp said: "I'd like to thank Kieron for his services to QPR.
"If he can stay clear of injuries I'm sure there's clubs out there that will offer him the chance to play football.
"He wasn't in my plans and I think he's got something to offer someone, so we wish him all the best."
Dyer scored his first QPR goal in their 1-1 draw with West Brom in the FA Cup third round on Saturday.