Trivia about Superman/Batman: Apocalypse.
- In Big Barda's closet, you can see the costume that belongs to her husband, Scott Free aka "Mr. Miracle".
- On Apokolips, Batman uses a rather distinctive flying harness. It is the same flying harness that is used by "Orion", the son of Darkseid raised to be the greatest enemy of Darkseid and Apokolips.
- During the battle on Paradise Island, Wonder Woman yells "Amazons Attack!" That was the name of a DC storyline where the Amazons were tricked into invading "Man's World", featuring a major Amazon assault on Washington, D.C.
- Much of the plot (Kara's arrival on Earth, her time with the Amazons, the kidnapping by Darkseid) is actually a review of the introduction of the modern incarnation of "Supergirl" as seen in earlier issues of the "Superman/Batman" comic. This is currently no longer considered canonical after DC's reboot in 2011 due to Supergirl's origin being changed in the "New 52" storyline when the issue was released in September 2011.
- This marks the third time that Superman, Batman, and Wonder Woman have been teamed up together in an animated movie. The first was Justice League: New Frontier, and the second was Crisis on two Earths. On another note this is the first time that they were featured without any of the other founding members of the Justice League.
- The first project that Kevin Conroy and Susan Eisenberg (Batman and Wonder Woman) have worked on together since the end of the Justice League series.
- Takes place after the events of Batman/Superman Public Enemies, as it mentions the impeachment of President Luthor and the giant Kryptonite meteor that threatened the Earth in that movie.
- Though the film closely follows the original comic book storyline re-introducing the Supergirl character, there are three scenes omitted from the film. The first depicts a battle between Batman and Artemis, which occurs in the park when the Amazons attempt to kidnap Kara from Superman. In the battle Artemis is close to winning a hand-to-hand fight with Batman. Before being defeated Batman resorts to using a dart gun on Artemis in order to gain the upper hand. The second scene that is skipped is the fight between SPOILER: Superman and Supergirl. In this fight instead of using a 'clap' sound wave attack Superman takes a Kryptonite ring out of his belt buckle and puts it on to harm Kara, although harming himself in the process. The third omitted scene depicts Wonder Woman as being involved in defending Kara from Darkseid on the Kent farm near the end of the film. Instead of Darksied being sent into space, in the original comic he is duped into believing his Omega Beams had destroyed Kara and Superman fights with him while dragging Darkseid through space in anger before trapping Darkseid in the source wall which is located at the end of the universe.
- Coincidentally, this movie was released the same week that Clark and Kara teamed up again to fight Darksied on the WB's Smallville. However the plot of the Smallville episode was the reverse of what it was in the movie, where instead of Clark saving Kara from Darksied, it was the other-way around.
- When Kara and Superman are speaking Kryptonian it's actually Esperanto, an international constructed language similar to German.
- The ending of the film regarding Kara's ceremony for her official appointment as Supergirl was handled differently from the original comics. In the film only Batman, Superman, Wonder Woman, Big Barda, and the Amazons attended the ceremony. In the comics, several of Earth's other superheroes (including Superboy, Robin, and Nightwing) made cameo appearances to also attend the ceremony.