- Accidental Nightmare Fuel: Ed's mouth flaps sometimes cross into this territory, due to the relative crudeness of the stop-motion animation.
- Bizarro Episode: The episode "Mako" revolves around an animated alien who comes to earth and takes over the bodies of whoever it goes inside. Its victims have no memory of what happens when the alien takes over them.
- Ear Worm: The theme song is the reason most people remember this show.
- Epileptic Trees: It's possible to interpret Mister Ed as the deranged hallucinations of a man who owned a completely normal horse, but in-universe evidence that Ed can talk is much stronger.
- Fetish Fuel Station Attendant: Connie Hines as Wilbur's wife Carol. One episode had her doing alterations on a dress and she had the skirt hiked up to her thighs.
- Hilarious in Hindsight: If you watch the series carefully, you'll notice that Alan Young is quite skilled at doing foreign accents. Guess who he had to do a Scottish accent for many years later?
- They Copied It, So It Sucks: Some viewers found this a blatant ripoff of several films in which Donald O'Connor had adventures with "Francis the Talking Mule."
- Urban Legend of Zelda: Snopes.com, for a joke, posted a page that Ed was really played by a female zebra named Amelia.