Scooby-Doo on Zombie Island is a 1998 American direct-to-video animated mystery comedy horror film based on the Scooby-Doo franchise. In the film, Shaggy, Scooby, Fred, Velma and Daphne reunite after a year-long hiatus from Mystery, Inc. to investigate a bayou island said to be haunted by the ghost of the pirate Morgan Moonscar. The film was directed by Jim Stenstrum and written by Glenn Leopold, based on a story by Leopold and Davis Doi.

Scooby-Doo's popularity had grown in the 1990s due to reruns aired on Cartoon Network. The channel's parent company, Time Warner, suggested developing a direct-to-video (DTV) film on the property. The team at Hanna-Barbera, collaborating with Warner Bros. Animation (which was in the process of absorbing Hanna-Barbera at the time), consisted of many veteran artists and writers. Many of the original voice actors of the series were replaced for the film, although Frank Welker returned to voice Fred Jones. It was also the first of four Scooby-Doo direct-to-video films to be animated overseas by Japanese animation studio Mook Animation. Rock bands Third Eye Blind and Skycycle contribute to the film's soundtrack. The film is dedicated to Don Messick, Scooby-Doo's original voice actor who died in October 1997.

Zombie Island contains a darker tone than most Scooby-Doo productions, and is notable for containing real supernatural creatures rather than people in costumes. The film was released on September 22, 1998 and received positive reviews from critics, who complimented its animation and its story. The film is also notable for being the first Scooby-Doo production featuring the entire adult gang (sans Scrappy-Doo) since The New Scooby-Doo Mysteries episode A Halloween Hassle at Dracula's Castle, which premiered on ABC on October 27, 1984. The film was aided by a $50 million promotional campaign, and sponsorship deals with multiple companies. Sales of the film on VHS were high, and it became the first in a long-running series of DTV Scooby-Doo films. The film made its first TV debut on October 31, 1998 on Cartoon Network.

A sequel, Scooby-Doo! and the Witch's Ghost, was released in 1999, while two decades after the film's release, Warner Bros. Animation developed a stand-alone sequel/retcon reboot Return to Zombie Island from a different creative team, released in 2019.