Richard Dunne, Brian Murphy, Shaun Wright-Phillips and Bobby Zamora are also to be released when their contracts expire.
The Loftus Road club have offered new deals to 36-year-old defender??Clint Hill and Alejandro Faurlin and preliminary discussions have taken place with those two players.
Midfielder Karl Henry has until June 30 to exercise his contractual option of a further year.
Loanees Mauricio Isla, Niko Kranjcar, Eduardo Vargas and Mauro Zarate have also all returned to their parent clubs.
Boss Chris Ramsey had previously said that he expected there to be a fairly big turnover in personnel at the club as QPR prepare for life in the Championship next season.??
Barton joined QPR four years ago from Newcastle United and made 99 appearances for the R???s.??
He spent the 2012/13 campaign on loan at French side Marseille but returned to help the club secure promotion to the Premier League the following season.
Ferdinand spent just one season at Loftus Road after leaving Manchester United, with the 36-year-old making 12 appearances for QPR.
Wright-Phillips made 74 appearances during his four-year stay at Loftus Road, while Bobby Zamora will probably always be remembered by QPR fans for scoring the play-off final goal last season that secured his side???s return to the Premier League.
Brian Murphy who joined QPR from Ipswich in August 2011, made just six appearances for the club while 35-year-old Dunne played a key role in the club???s promotion-winning campaign in 2013/14.
A message on the club???s official website also thanked those who had been released for their service.
It read: ???The club would like to thank all the players for their contribution to QPR and wish them every success in the future.???