Dragon Quest, published as Dragon Warrior in North America until 2005, is a series of Japanese role-playing video games created by Yuji Horii and his studio Armor Project. The games are published by Square Enix (formerly Enix), with localized remakes and ports of later installments for the Nintendo DS, Nintendo 3DS, and Nintendo Switch being published by Nintendo outside of Japan. With its first game published in 1986, there are eleven main-series games, along with numerous spin-off games. In addition, there have been numerous manga, anime and novels published under the franchise, with nearly every game in the main series having a related adaptation.

The series has had a significant impact on the development of console role-playing games, and introduced a number of features to the genre. Installments of the series have appeared on various computers, consoles, handheld devices, and mobile phones. Early in the series, the Dragon Quest games were released under the title Dragon Warrior in North America to avoid trademark conflict with the unrelated tabletop role-playing game DragonQuest. Square Enix did not register the Dragon Quest trademark for use in the United States until 2002.

The basic premise of most Dragon Quest games is to play a hero who is out to save the land from peril at the hands of a powerful evil enemy, with the hero usually accompanied by a group of party members. Common elements persist throughout the series and its spinoff games: turn-based combat; recurring monsters, including the Slime, which became the series' mascot; a text-based menu system; and random encounters in most of the main series.

Dragon Quest has had the same general lead development team since its inception in the 1980s, as scenario writer and game designer Yuji Horii, character designer Akira Toriyama, and music composer Koichi Sugiyama have handled their respective roles on every major game in the series. The original concepts, used since the first game, took elements from the Western role-playing games Wizardry and Ultima. A great deal of care was taken to make the gameplay intuitive so that players could easily start to play the game. The series features a number of religious overtones which were heavily censored in the NES versions outside of Japan.

Anime version

There are two major television series that were adapted from the games. Dragon Quest began airing in December 1989, and ran for 43 episodes. It was supervised by Horii, with a story loosely based on Dragon Quest III. The first 13 episodes of the series were translated into English by Saban Entertainment under the title Dragon Warrior. Due to its early time slot, and a lawsuit filed by Toriyama for not being credited for his work on character designs, it was not renewed. A second anime series, Dragon Quest: Dai no Daibōken, based on the manga of the same name, was produced by Toei Animation. It ran for 46 episodes from October 17, 1991 to September 24, 1992. On April 20, 1996, a film titled Dragon Quest Saga – The Crest of Roto was released. A 3DCG movie based on Dragon Quest V, Dragon Quest: Your Story, released in Japan in August 2019.