Swamp Thing is an animated television series based on the Vertigo/DC Comics superhero character Swamp Thing. The series is short-lived, with the pilot episode airing on October 31, 1990 followed by four additional episodes airing weekly from April 20 to May 11, 1991. It aired on YTV from 1991 to 1993 in Canada. Produced by DIC Animation City, the series corresponded with Kenner's Swamp Thing action figure collection released in 1990. Despite the animated series' brief run, various merchandise was also produced in 1991 resulting in the only significant marketing platform ever created for the character. This is the final animated series from DC Comics to not be produced by Warner Bros. Animation.

Anton Arcane takes the role of the main villain responsible for Alec Holland's transformation into the Swamp Thing. Arcane is backed by his gang of Un-Men: Dr. Deemo, Weedkiller, and Skinman.

The Swamp Thing also has two friends named Tomahawk and Bayou Jack. Tomahawk is Native American and should not be confused with the DC/Vertigo character, Thomas Hawk, who was a soldier in the American Revolution rescued by Native Americans. Bayou Jack is a Vietnam veteran.

Similar to Troma's Toxic Crusaders, the animation style of Swamp Thing follows the trend of goofy, horror anti-heroes made for children. Spoofing Chip Taylor's "Wild Thing", the opening theme plays "Swamp Thing! ...You are amazing!"

Swamp Thing was apparently turned down by CBS, leading to its mid-season debut on FOX. Despite the series limited number of episodes, NBC featured it during Chip and Pepper's Cartoon Madness in fall 1991, and the Sci Fi Channel would syndicate it years later. The United Kingdom's Children's Channel also re-aired Swamp Thing in the 1990s.

The animated series aired concurrently with a more successful live-action adaptation of the comic book.