Yu-Gi-Oh! Capsule Monsters is a 12-episode mini-series commissioned and produced by 4Kids Entertainment in the United States, and animated by Studio Gallop in Japan shortly after the conclusion of the original series. This miniseries is an addendum to the first half of the final season of the anime, taking place after Grand Championships but before the climactic Dawn of the Duel arc. The miniseries was produced exclusively for international broadcast, making it the only anime series in the Yu-Gi-Oh! franchise to not see a release in Japan. A short-lived board game, Yu-Gi-Oh! Capsule Monsters Collectible Figure Game, was created based on this mini-series.

Yu-Gi-Oh! is a Japanese manga series written and illustrated by Kazuki Takahashi. It was serialized in Shueisha's Weekly Shōnen Jump magazine between September 1996 and March 2004. The plot follows the story of a boy named Yugi Mutou, who solves the ancient Millennium Puzzle. Yugi awakens a gambling alter-ego or spirit within his body that solves his conflicts using various games.