The 34-year-old Cesar joined Toronto in February after playing sparingly under Harry Redknapp at QPR. His return to the Premier League was announced Friday.
Cesar conceded nine goals in seven matches with Toronto this season.
He also played in all of Brazil's matches at the World Cup, making two crucial saves to beat Chile in a penalty shootout in the second round.
The Brazilian joined QPR from Inter Milan on a four-year deal in August 2012.
QPR secured a return to the Premier League in May, a year after being relegated.