The 26-year-old right back, who featured for Chile at the World Cup, is expected to complete a medical with the London club on Sunday ahead of a season-long loan.
The 26-year-old, who can operate both in midfield and in defense, will finalize his move to Loftus Road once a medical is completed on Sunday, according to Juventus CEO Giuseppe Marotta.
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"We have reached a deal with QPR for Isla to move on loan. Tomorrow he will have medical with QPR," Marotta told reporters at a press conference.
The Chile international was a strong performer in his country's recent World Cup campaign but had failed to hold down a regular position at club level for Juventus, having joined from Serie A rival Udinese in 2012.
Earlier in June, he conceded his future in Turin depended on then-manager Antonio Conte, but he has now been allowed to move to the Premier League by new boss Massimiliano Allegri.
Isla follows Rio Ferdinand and Steven Caulker through the door at Loftus Road as manager Harry Redknapp prepares his club for the new season. The club opens its league campaign at home to Hull City on August 16.