The character found perhaps its greatest popularity during the original 1970s Wein/Wrightson run and in the mid-late 1980s during a highly acclaimed run under Alan Moore, Stephen Bissette, and John Totleben. Swamp Thing would also go on to become one of the staples of the Justice League Dark team of magical superheroes.

The character has been adapted from the comics into several forms of media, including feature films, television series, and video games. The characther made its live-action debut in the film Swamp Thing (1982), with Dick Durock playing the Swamp Thing, while Ray Wise played Alec Holland. Durock played both Swamp Thing and Holland in the sequel film The Return of Swamp Thing (1989). Durock reprised the role again in the television series Swamp Thing (1990). The Swamp Thing was played by Derek Mears with Andy Bean playing Alec Holland in the television series Swamp Thing (2019).

In the swamps of Louisiana, Dr. Alec Holland works with his sister Linda on a top-secret bio-engineering project to create a plant/animal hybrid capable of thriving in extreme environments. Government agent Alice Cable arrives just as Holland makes a major breakthrough, and begins to develop feelings for him. However, a paramilitary group led by the evil Dr. Anton Arcane, who is obsessed with immortality, kills Linda while trying to steal the formula for their own purposes. During the attack, Alice escapes and Alec is covered in chemicals, caught on fire, and runs screaming in the swamp, presumably to die. However, he returns as a monstrously mutated plant creature. As the Swamp Thing, Holland battles Arcane's forces to protect Cable, and eventually takes on the mad doctor himself, who has also mutated from his incomplete understanding of the Holland formula.

The Alec Holland incarnation of the Swamp Thing appeared in a self-titled 1982 live-action film, with Holland portrayed by Ray Wise and Swamp Thing portrayed actor / stuntman Dick Durock. This version of Holland was turned into Swamp Thing by Anton Arcane in a laboratory accident.

The Alec Holland incarnation of Swamp Thing appeared in the live-action sequel film The Return of Swamp Thing, with Dick Durock reprising the role and Ray Wise reappearing in a flashback using footage from the 1982 film. This version of Swamp Thing is Holland's consciousness reconstituted through plant life.

Rumors in November 2012 suggested that Guillermo del Toro was working on a Justice League Dark film titled Heaven Sent. It would feature Deadman, the Spectre, Swamp Thing, John Constantine, Phantom Stranger, Zatanna, Zatara, Sargon the Sorcerer, and Etrigan the Demon. Del Toro later confirmed in January 2013 that he was working on such a film, with the working title, Dark Universe, and was hiring a screenwriter. Del Toro revealed Swamp Thing, Constantine, The Spectre, Deadman, Zatanna and Zatara were characters in the story.