Wanda Ventham, Number 8 in the Prisoner, and from UFO.
Edit: a few people have pointed out the person in the top image is actually Honor Blackman. To which I say…no, it’s still Wanda Ventham. The two women do look alike, though. Here’s another image in different lighting in the same outfit so you can see the difference:
Additional Edit: A couple people have pointed out something I didn’t know: Wanda Ventham is Benedict Cumberbatch’s mother. Really.