The giant monster the Fantastic Four fight during the montage at the beginning of the movie is a nod to the cover of Fantastic Four #1 (1961)
Four actors from the unreleased Les Quatre Fantastiques (1994) movie have cameos: Alex Hyde-White (Reed Richards), Jay Underwood (Johnny Storm), Rebecca Staab (Susan Storm) and Michael Bailey Smith (Ben Grimm). Hyde-White and Staab provide voice-overs as newscasters, while Underwood and Bailey Smith portray construction workers look up at the Human Torch during the opening montage (with Underwood saluting his 2025 counterpart). All four of them also make a brief appearance standing together in period outfits saying "Thank you, Fantastic Four!" later during the same montage.
The Excelsior rocket, which Reed, Ben, and Susan and Johnny Storm take to space, was named after the catchphrase of Marvel founder Stan Lee. In the comics, the rocket was named "Marvel-1".
The film takes place within the Marvel Cinematic Universe on Earth-828. The number designation comes from "Fantastic Four" co-creator Jack Kirby's birthday August 28.
The HERBIE robot was portrayed through a combination of a wooden puppet, a remote-controlled animatronic with a functioning head and arms, and computer-generated imagery.