Griffin, 24, the youngest of three brothers who have all played for the Red Devils, has signed a two-year extension with an option for a third year.
Salford coach Ian Watson said: "George has been the model of consistency during his time at the club. He was a key part of our squad last season and held the pack together alongside Craig Kopczak.
"George is still a young player and is developing all the time. His current levels of performance will just be the start."
More than happy to be staying at Salford for atleast 3 more years 👀😂 got something special going here . Thanks for the messages everyone 🖒— George Griffin (@georgegriffin4) May 19, 2017