Which 2001 computer-animated film was based on the Final Fantasy franchise?

The 2001 computer-animated film based on the Final Fantasy franchise was Final Fantasy: The Spirits Within.

Directed by series creator Hironobu Sakaguchi, the film was produced by Square Pictures and released by Columbia Pictures in 2001. Rather than adapting one numbered game, it tells an original science-fiction story about scientist Aki Ross, Doctor Sid, and humanity’s struggle against alien Phantoms on a devastated Earth. Its setting and plot are separate from the games’ recurring worlds and characters.

The film was a major technical project. It used photorealistic computer animation, took roughly four years to complete, and required a render farm of 960 workstations for its 141,964 frames. Its reported $137 million production cost far exceeded its box-office return, and the financial loss contributed to the closure of Square Pictures. It is often confused with later Final Fantasy animated projects, including Final Fantasy VII: Advent Children and Kingsglaive: Final Fantasy XV, which are tied to particular games.