Dragon Quest (ドラゴンクエスト ,Doragon Kuesuto), published as Dragon Warrior in North America until the 2005 release of Dragon Quest VIII: Journey of the Cursed King, is a series of role-playing games created by Yūji Horii and published by Square Enix (formerly Enix). Installments of the series have appeared on MSX computers, Famicom/NES, Super Famicom/Super NES, Game Boy Color, Game Boy Advance, Nintendo DS, PlayStation, PlayStation 2 and Wii video game consoles, as well as on several models of mobile phone. As of February 2009, the Dragon Quest series has sold nearly 45 million units worldwide. It is Square Enix's second most successful franchise after Final Fantasy and is one of the most popular video game franchises in Japan.

Dragon Quest's North American name was changed due to a trademark conflict with the role-playing game DragonQuest, which was published by veteran wargame publisher SPI in the 1980s until the company's bankruptcy in 1982 and purchase by TSR, which then published it as an alternate line to Dungeons & Dragons until 1987. In 2003, Square Enix registered the Dragon Quest trademark in the US, making the Dragon Warrior name obsolete.