- Actor Allusion: Fubuki Tenjouin/Atticus Rhodes isn't the first character associated with Red and Black that Koji Yusa and Jason Griffith have both voiced. Similarly, Dr. Allbert Zweinstein is played by Takeshi Aono, and guess who else he played? note
- Anime First: Also, it's the first original Yu-Gi-Oh! anime series.
- In episode 35 Slade and Jaeger state that Chazz can only use monsters with no more than 500 Lifepoints in their duel instead of attack points.
- In episode 143, The Supreme King uses "Dark Calling" against O'Brien/Axel, fusing "Elemental Hero Burstintrix" from his hand and "Elemental Hero Clayman" from his graveyard to fusion summon "Evil Hero Infernal Sniper". The problem is, at no point prior is The Supreme King shown actually sending "Clayman" to the graveyard, or even sending an unspecified card to the graveyard that might have been "Clayman".
- In the dub, Jesse mixes up attack points and life points several times. It's not called attention to, so it must be a mistake, but he does it almost once every duel.
- Cross-Dressing Voices: Both Sho and Johan are voiced by female seiyuus in the Japanese version.
- Executive Meddling: Both the anime and the manga had the tail end of the series rushed due to the execs wanting to push out the newer Yu-Gi-Oh! series (5Dís and ZEXAL respectively).
- This also affected the dub of GX, as 4Kids Entertainment was forced to Cut Short their English dub of GX after the third season and skip ahead to dubbing Yu-Gi-Oh! 5Ds at the behest of Japanese broadcasters who wanted the new series to get pushed to the West as soon as possible.
- Fake Brit: Bastion Misawa in the dub.
- Vellian Crowler leans towards this, but has more of a mid-Atlantic accent associated with Ivy League professors. In Japanese he was actually Italian.
- Lyman Banner is a Fake German in the dub.
- Incidental Multilingual Wordplay: One-shot character Anger Mask uses, as his key monster, a card called "Ikari no Anchor Knight", an armored warrior that fights with anchors as a Visual Pun on the word "ikari" which can mean both "anchor" and "anger". The pun works almost as well in English, where "anchor" and "anger" are near-homophones.
- Missing Episode: When Pluto TV began airing their Yu-Gi-Oh! Channel, some episodes of GX were missing. Episodes 11, 16, 19, 23, 29, 30, 36, 39, 46, 49, 56, 57, 59, 66, 105, and 150-155 are all skipped, with no real reason given.
- No Export for You: The fourth season has never been dubbed or released on DVD outside Japan.
- Seasons 2-3 have never been aired in Finland, even though the first season was aired in Finland. Then again, the original Duel Monsters series has never been aired in Finland either.
- The Other Darrin:
- Yu-Gi-Oh!: Bonds Beyond Time replaced Cassandra Morris from the anime with Eileen Stevens.
- Chazz and Alexisí English VAís were replaced later on.
- When Chumley reappears in Season 2, he's voiced by Tom Wayland, as opposed to his original voice actor, Ted Lewis.
- She Also Did: Jasmine's English voice actress, Suzanne Goldish, would also go on to direct a few anime dubs with the L.A-based Studiopolis, including Bleach (episodes 268-366), K, Kabaneri of the Iron Fortress, Tiger & Bunny, and Sailor Moon (2014 re-dub).
- Matthew Labyorteaux, Jaden's voice actor in the English dub, had previously done quite a bit of acting work outside of voice acting, his most well-known role being Albert Quinn Ingalls on Little House on the Prairie.
- Star-Making Role: The anime happens to be KENN's debut and breakout role.
- What Could Have Been: Yu-Gi-Oh! VS. GX was a canceled movie that would have pit Yugi against Jaden. A lot of its plot points were incorporated into the second season - most obviously, the Domino Field Trip miniarc.
- The Wiki Rule: Yugipedia (which forked from the old wiki in 2018).
Trivia / Yu-Gi-Oh! GX