In 1983, German producer Bernd Eichinger met with Stan Lee to explore obtaining a movie option for the Fantastic Four, which his company Constantin Film acquired three years later for an estimated $250,000.

When his film rights option was about to expire in 1992, Eichinger commissioned B-movie producer Roger Corman to make a low-budget version called The Fantastic Four just to retain the rights; this 1994 film was promoted with a trailer and cast tour but was never officially released, and the cast reportedly had no idea it was only made to preserve the license.

Marvel, along with Avi Arad and Ralph Winter, paid to acquire the negative of the unreleased Corman film so that 20th Century Fox could proceed with a proper big-budget adaptation.

The project went through numerous directors before Tim Story, including Chris Columbus (who says he was fired after suggesting the film be based on Jack Kirby's Silver Age art), Peter Segal, Sam Weisman, Raja Gosnell (who left to direct Scooby-Doo instead), and Peyton Reed, who developed a version influenced by A Hard Day's Night and later reused ideas from it for Ant-Man and the Wasp: Quantumania.

Mads Mikkelsen auditioned for the role of Reed Richards, calling the experience 'humiliating,' before Ioan Gruffudd was cast instead.

Robert Downey Jr. was initially considered for the role of Doom in the 2005 film, decades before eventually playing the character in the MCU's The Fantastic Four: First Steps (2025).

Sean Astin, despite never having directed a feature film and being unfamiliar with the comics, campaigned to direct the movie; though he didn't get the job, he impressed studio executive Tom Rothman with his determination. Astin had wanted Christina Aguilera and Cameron Diaz for Sue Storm, but Diaz declined because she didn't want to wear superhero makeup.

Michael Chiklis insisted on portraying The Thing entirely through practical effects and makeup rather than CGI.

Hugh Jackman reprises his Wolverine look in a deleted scene where Reed Richards morphs his face to resemble Jackman's X-Men character to impress Susan Storm; the scene was cut from the theatrical release but restored in the Extended Cut, and was intended to build toward a shared cinematic universe between Fox's X-Men, Spider-Man, and Fantastic Four franchises.

Jessica Alba stated in 2025 that she felt humiliated filming a nude scene for the movie.

Director Tim Story decided to make significant script changes and add more special effects after watching Pixar's The Incredibles (2004) to avoid similarities between the two films.

A deleted storage-room scene shows a robot meant to represent H.E.R.B.I.E. from the 1978 Fantastic Four animated series.

Fantastic Four was the highest-grossing superhero film directed by an African-American director until Ryan Coogler's Black Panther in 2018.

The film's critical reputation improved over time after the poorer reception of the 2015 reboot.