- Actor Allusion: That janitor named Glenn...Doesn't he sound familiar?
- Word of God even says that the janitor from Scrubs actually is named Glenn Matthews, and confirms that he got the name from the character from Clone High.
- Channel Hop: Began production at Touchstone Television and was going to be aired on ABC. Disney relinquished the rights when Miller and Lord took the series to MTV. Touchstone still got credit, though.
- Credits Gag: Pun Dog (script coordinator Adam Pava's nickname)
- Descended Creator: Phil Lord, Chris Miller, and Bill Lawrence as Scudworth, Mr. Butlertron, and head of the Secret Board of Shadowy Figures respectively.
- Development Hell: See below. Phil Lord and Chris Miller blame a messy copyright situation for stagnating any efforts for a revival.
- Keep Circulating the Tapes: The complete series DVD was only released in Canada, but quickly went out of print. It did eventually make it to iTunes and Amazon Prime, however.
- No Export for You: Averted to an extent in the United States as the Canadian DVD release can be legally imported into that country and play on all standard (NTSC) DVD players, as Canada is also in Region 1.
- Popularity Polynomial: The show has been on a recent upswing in terms of popularity, helped by co-creators Phil Lord and Christopher Miller going on to make 21 Jump Street and The LEGO Movie.
- Production Posse: Several of the voice actors were from Scrubs, another Bill Lawrence produced show, and Will Forte has shown up in a couple other Phil Lord/Chris Miller productions since, including one where he played Abe Lincoln again.
- Protection from Editors: Despite (or rather because of) MTV's complete lack of interest and support in this show, the creators have admitted that they were never scrutinized by Standards and Practices and were basically given carte blanch to do whatever they wanted.
- Reality Subtext: A running theme of the show is the clones angsting over having to live up to the reputations of their famous namesakes, with Gandhi being one who takes it the hardest. Appropriate, since the fact that Mahatma Gandhi is still revered to almost god-like status in India is what got the show canceled.
- Screwed by the Lawyers: Copyright tie-ups between Touchstone Television, MTV and Nelvana, as well as Miller and Lord having their own contracts to fulfill for Warner Bros. and Sony, respectively, are the main reason a revival is presently out of the question.
- Screwed by the Network: MTV made no hesitation dropping the show, which was already pulling mediocre numbers, when the Gandhi protests happened.
- Throw It In!
- Tom Green ad libbed the "albatross" bit in the "ADD" episode. This grew out of a joke he made with the director, saying "This is a cartoon, right? So I can be anything? Even... an albatross??"
- Scudworth's emotional breakdown over his call from John Stamos was mostly Phil Lord ranting about most of his own minor insecurities, such as how messy his car was and how he keeps forgetting his card when going to the submarine sandwich restaurant.
- Troubled Production: According to the cast and crew at the 15th Anniversary in 2017, there were problems working around each others schedules for their projects. Christa Miller recalls working on Clone High, Scrubs, and Drew Carey within the same week that she briefly developed amnesia.
- What Could Have Been
- According to this interview, several plans for season 2 and 3 were made, such as another addition to the Love Triangle, possibly an older teacher clone, Gandhi revealed as being the clone of Gary Coleman instead of Mahatma Gandhi due to a DNA mixup, and time travel used to extend the clones high school years in a parody of Beverly Hills, 90210.
- Mr. Butlerton was originally named Mr. Belvetron, hence why he calls everyone "Wesley."
- Word of God: This interview with the creators reveals a few things. The overall plot they had for the series was for season one to be junior year, season two the first half of senior year, season three the second half, and at the end they would go through a wormhole and repeat senior year in season four, and if there was a season five, they'd make it college.
- It also states that season two could've started out with the three main characters walking like in the pilot (except to senior year), having forgotten what had happened over the course of the summer, and putting the pieces of the puzzle together to find out how they got out of the cliffhanger.
- Also, due to the controversy of Gandhi's character, the creators had to pitch two alternatives of the show to MTV, one where Gandhi mysteriously disappears and turns out to have somehow sacrificed himself in the meat locker to save his friends, which would just altogether drop his character from the show, and the other where they keep the character while writing in that there was a mix up in the lab and Gandhi is actually the clone of Gary Coleman.
- Writer Revolt: One of the few notes that the creators got from MTV was that the first episode didn't establish who the characters were meant to be clones of, which is why they all address one another by their full names in the second episode.
Trivia / Clone High