Quote Originally Posted by Bojay1997 View Post
Actually, it was an "official" Bond film, it just was from a different producer/production entity. One of the writers of Thunderball apparently had film rights to the underlying literary material. MGM which owns the Bond film rights now owns this one as well.
They had the legal right to make the film so it's a James Bond film, but it isn't considered "official" as in cannon like the rest of the films. It's as official as the 1967 Casino Royal starring David Niven, Woody Allen, and Peter Sellers.