The following actors/actresses were both in the original Twilight Zone and Columbo. I'm sure there were more, but I haven't gone through all five seasons:
William Shatner - "Fade into Murder", "Butterfly in Shades of Grey"
Peter Falk! 1961 Episode "The Mirror."
These are two of the greatest TV programs, IMO, and there are likely other links between them to discuss. Great topic.
There’s a TZ episode where a man gives people at a bar something and whatever he gives them ends up being important or something like that. Arlene Martel is a girl at the bar. As you said before, the list of actors who did both shows is huge. It’s funny how I didn’t even think of Peter Falk until it was mentioned above. I just ran through the list of killers and forgot about the star.
Don Keefer was the coroner in "The Most Crucial Game" and "Death Lends A Hand," and also in one of the most famous TWILIGHT ZONE'S. He was the man who becomes a jack in the box in It's A Good Life."