This is the first feature film to have a fully computer-generated visual effects character in a leading role.
The town of Friendship, Maine is the name of a real village in mid-coast Maine, near Camden and Rockport, where scenes from the movie were filmed.
A deleted portion of the attic scene involved Kat coming across an old photograph of Casper's uncles Stretch, Fatso, and Stinkie when they were still humans. This was featured and shown in the storybook released alongside the film.
During filming, Bill Pullman and Christina Ricci had to talk to tennis balls in place of the ghosts, while the ghosts were added later on.
James and Kat Harvey are named after Harvey Comics, the long time publisher of "Casper the Friendly Ghost."
Don Novello: As Father Guido Sarducci (from Saturday Night Live (1975)), the Catholic priest Carrigan Crittenden hires to perform an exorcism on the mansion.
Rodney Dangerfield: One of the people into whom Dr. Harvey turns while possessed by The Ghostly Trio.