Trollhunters: Tales of Arcadia is an American animated fantasy television series created by Guillermo del Toro, distributed by DreamWorks Animation Television and Double Dare You Productions, and produced by Netflix. It was based on the 2015 novel Trollhunters by del Toro and Daniel Kraus. It follows the story of James "Jim" Lake Jr., a teenage boy who finds a mysterious amulet and stumbles across a secret realm inhabited by trolls and other magical creatures. Soon afterward, he and his friends are charged with protecting the world from the dangerous monsters that lurk in the shadows of their small suburban town.

The first two episodes of the series premiered on October 8, 2016, at the New York Comic Con. The first season was released on Netflix worldwide on December 23, 2016. The second season premiered on December 15, 2017. The third and final season premiered on May 25, 2018.

Since its release, Trollhunters has been widely praised as an ambitious and boundary-pushing animated series. The series was nominated for nine Daytime Emmy Awards in 2017, winning more than any other animated or live-action television program that year. In its first three seasons, it has also received or been nominated for a BAFTA Award, several Annie Awards, Kidscreen Awards, Golden Reel Awards, and a Saturn Award. The show has also spawned several original children's books and has been adapted into a series of graphic novels by Marc Guggenheim and Richard Hamilton, released by Dark Horse Comics.

Anton Yelchin was part of the series through the first two seasons, as he had recorded enough dialogue to complete them before his sudden death. Yelchin was also able to provide a portion of dialogue for the final season, while the remaining portions of dialogue were recorded by Emile Hirsch.

Following the show's success, Guillermo del Toro announced that Trollhunters would be the first chapter in a trilogy of television series, collectively titled Tales of Arcadia. The story was continued in a science fiction inspired follow-up series entitled 3Below: Tales of Arcadia, and the trilogy concluded in a fantasy series entitled Wizards: Tales of Arcadia. It also premiered on Pop in the UK on September 3, 2018.

A full-length feature film, titled Trollhunters: Rise of the Titans, was released on July 21, 2021.