The Worst Witch, on ITV (UK) / HBO (USA)
Halloween Specials.net; IMDb; Kindertrauma; TV Tropes; Wikia; Wikipedia

This came out in 1986, but I never saw it until... I dunno, must have been sometime in the 20-aughts, I guess. I vaguely recall at some point around that time seeing a bit of a TV series of the same name, which had originally aired in 1998. Both the TV movie and the TV series were based on a series of books that I've never read. The reruns were airing on a Canadian channel I used to watch sometimes. And the movie... I believe I found it on VHS at my cousins' camp at the lake, one summer, and watched it there. I don't honestly remember which I saw first. What I can tell you is that they're both about a witches' academy, you know, for young girls training to be witches. The main one was Mildred Hubble, who in the movie was played by Fairuza Balk. The cast also included Diana Rigg, Tim Curry, and Charlotte Rae (from such comedy nostalgia as "Diff'rent Strokes" and "The Facts of Life"). Also one of the girls was played by Sophie Cook (whom I knew from The Chronicles of Narnia, though I wasn't aware of that until I rewatched that in 2014). It all sounds like it should be a decent movie. It's got a good cast, a good premise, and witches. Lots of cute little witches. But... I don't really remember anything about the movie except thinking it turned out to be incredibly lame. Like, mind-bogglingly lame. (The series was probably less lame, but I never saw much of it, and what I did see, I wouldn't exactly call "good.") Nevertheless, I might like to see the movie again sometime, to write up a proper review. At the very least I can say, I really like the Kindertrauma article linked to above.