Ed Bishop, Michael Billington, Vladek Sheybal, Grant Taylor, Steven Berkoff, and Shane Rimmer all appeared in the James Bond series of movies. In addition, Lois Maxwell appeared on two UFO episodes ("The Cat with Ten Lives" and "The Man Who Came Back") as Straker's alternate secretary Miss Holland.
There is something else. In the wood I found a dog. It was horribly mutilated. Whatever did that...
Although set (and filmed) in England, all the futuristic cars are left-hand drive, and everyone drives on the right-hand side of the road. Several other series by the Andersons featured the same driving system, presumably because England was predicted to switch over sometime before the future events depicted. Flashback scenes showed the "normal" English driving arrangement.
During the opening theme, the show's title "UFO" is flashed on the screen for only a fraction of a second. It appears "officially" on screen at the end of the teaser sequence.
Many episodes had censorship cuts for the Italian edition, for example Foster drunken in UFO: Ordeal (1970) or Straker's relationship with Jo Fraser in UFO: The Responsibility Seat (1971) and Freeman's many flirts and jokes about women.