Oops… 5 feet. Is that better?
Lancelot Link, Secret Chimp. I’m pretty sure they were all adults.
If you count 6’1" Pam Stone in a recurring role the average increases to 6’ even.
Land of the Giants could win either category. I’m not sure if they used regular sized actors with real giants, or regular sized actors and real 6" tall people.
Paraphrasing what’s easily my favorite Chandler comment. 
Note that this is the 1984 to 1992 version of Night Court. Note that in the 2023 to 2025 version, the judge is played by Melissa Rauch, who is 4’11". So was she cast to make up for the height of everyone in the first version?
There’ve been live-action Harlem Globetrotters shows, I’m sure those have to win for tallest.
Man, this totally blows my perception of him out of the water. I saw him on Cheers and Dave’s World and never noticed he was actually quite tall.
Strangely, I totally can tell that John Larroquettte and Richard Moll were pretty tall.
I have the same perceptual oversight. But if you go back and watch the shows, or even just search for photos of the cast, you can see that Larroquette and Anderson are about the same height. Maybe the problem is that on the show, they interact most often in the courtroom, where Anderson is sitting and Larroquette is standing (and the judge’s bench isn’t raised all that high, so Anderson’s head is only at the level of Larroquette’s shoulders).
I want to know how tall Mrs. Stone was supposed to be.
They also shoot the shows with heights adjusted by the camera angle, the shoes the actors wear, and in cases of extreme height difference one actor will stand in a hole or the other on a platform. This is done much less on TV than in the movies (especially with a hole), but you can find shows with actors known to be noticeably shorter or taller than average that appear to be the same approximate height.
Sitting and standing can make a huge difference for tall people based on their build. I’m only 6’ tall but I have short legs and a long torso and I had a long legged 6’4" friend and sitting next to each other we could see eye to eye.
in the reboot version Mrs. Stone (the new judge’s mother) was played by Faith Ford, who is listed as being 5’7".
Perhaps the character smoked while she was pregnant.