The half-back has signed a deal that will see him stay with the Super League club until his 32rd birthday.
Croft moved to England from Australia last year, following sints at Brisbane Broncos and Melbourne Storm.
Quoted by Salford's official website, he said: "I'm delighted to extend my time at Salford, I'm excited at what the future holds for the club."
Croft is the Super League's current Man of Steel award holder.