Remy joined QPR from Marseille in January but was unable to prevent the club from being relegated to the Championship last season.
Newcastle director of football Joe Kinnear last week confirmed that the Magpies were closing in on a deal to bring Remy to St James' Park after the Frenchman had asked to leave the club in order to play in the top flight.
"Loic Remy has joined Newcastle United on loan," read a statement on QPR's official website. "The Frenchman, who joined QPR from Marseille in January, will remain at St James Park for the duration of the 2013-14 season.
"Remy signalled his intentions to the club earlier this summer of his desire to play in the top flight in a World Cup year and following the recent addition of Charlie Austin to the R's ranks, a deal has now been agreed with Alan Pardew's side."
Remy scored six goals in 14 appearances during his brief stint at Loftus Road.