- Cast the Runner-Up: Crispin Freeman was originally considered for Koji in the English dub, but ended up voicing Koichi instead.
- Channel Hop: Because of the fact that Disney bought out Fox Kids/Saban a year prior, this one ended up airing on ABC Family and in the last season of Disney's weekday/sunday block on UPN stations, Disney's One Too (a spinoff of One Saturday Morning over on ABC, though by this time it had dropped that name). It likely didn't get onto ABC because Disney was contractually obligated to dub this season, and had no interest in the show otherwise; indeed, their primary goal was the acquisition of ABC Family, and it actually got promotion there (Disney didn't bother to make promos for UPN stations to use).
- No Export for You:
- Frontier didn't get aired in either Malaysia or Morocco. In Malaysia's case, it's kinda odd that this is the only series of the franchise that wasn't released, while the others didn't have any problems to do so.
- The manga adaptation only saw an English release in, of all places, Australia, and was not translated by Tokyopop, evident from the wildly inaccurate mistranslations and misnaming.
- The Other Darrin:
- Due to fear of damaging his voice from all of the shouting, Michael Reisz, Takuya's English voice actor, refused to voice EmperorGreymon, giving the job to Dave Wittenberg instead... only for there to be not nearly as much shouting for EmperorGreymon's scenes. Wittenberg also replaced Reisz as Takuya for the movie.
- A similar situation became close to happening for the Japanese version, when, exhausted from doing all of the pattern voices, Junko Takeuchi (Takuya) asked Hiroshi Kamiya (Kouji) to voice Susanoomon for her. However, Kamiya refused because Takuya is the main character and she should've do it, and the director overruled the request; as a result, Takeuchi voiced Susanoomon as it was originally planned.
- In the Italian dub, the first voice actor for Agunimon, Maurizio Romano, died after the first ten episodes and was replaced by Danilo Di Martino for the remainder of the series.
- Refitted for Sequel: The idea of the digimon combining human and animal forms was originally created as a Digimental stage in Digimon Adventure 02, but the producers abandoned it in one of the plot's many rewrites. Sagittarimon, who might have been included in Frontier as a nod, was one of the designed candidates and can be quickly recognized as a centauroid fusion of Flamedramon and Raidramon from 02.
- What Could Have Been:
- The first character design sketches released in the V-Jump magazine showed some of the characters with different color schemes. Additionally, Kouji was originally going to sport long, black slacks instead of the grey capri sweatpants he eventually dons in the show. One of the fanbooks reports that Kouji was originally going to be a female character, an idea that was presumably discarded because the previous season also had a female lone wolf (Ruki Makino).
- Crispin Freeman was originally considered for Koji in the English dub, but wound up playing Koichi instead. He would end up voicing The Lancer next season.
Trivia / Digimon Frontier