Dragon Quest III: The Seeds of Salvation, titled Dragon Warrior III when initially localized to North America, is a 1988 role-playing video game developed by Chunsoft and published by Enix. It is the third installment in the Dragon Quest series and was first released for the Family Computer (Famicom) in Japan and later for the Nintendo Entertainment System (NES) in North America. The game saw an enhanced remake for the Super Famicom (the Japanese release of the Super NES) in 1996 and the Game Boy Color in 2001, and a port to mobile phones and the Wii in 2009 and 2011. A version of the game for Android and iOS was released in Japan on September 25, 2014, and worldwide as Dragon Quest III: The Seeds of Salvation on December 4, 2014. It was the first time the game was given an official English subtitle. Later in 2021, another remake of the game titled Dragon Quest III HD-2D Remake, based on the HD-2D graphical style of Octopath Traveler (2018), was announced during the franchise's 35th anniversary livestream, and it was eventually released in November 2024 for Nintendo Switch, PlayStation 5, Windows, and Xbox Series consoles.

The first three Dragon Quest games are part of the same story, and Dragon Warrior III is the first game chronologically, as well as the third game that features the hero Erdrick (Loto in the Japanese releases and Game Boy Color localization). The story follows "the Hero" whose quest is to save the world from the archfiend Baramos. Gathering a group of companions into a party, the Hero must travel the world, stopping at various towns and locations, and make their way to the Demon Lord Baramos' lair.

Dragon Quest III is noted for greatly expanding upon the gameplay of the original Dragon Quest and Dragon Quest II. The game uses basic role-playing video game conventions such as leveling up by gaining experience points and equipping items. The battle system is turn-based like the other games in the series, though the remakes incorporate various interface changes from later titles. These include simpler door opening, a bag to store items instead of keeping them at a bank, quick item sorting with "Tidy Item" and "Tidy Bag" command, and a "Full HP" command to automate the process of casting healing and status restoring spells. And while earlier Dragon Quest games were non-linear in structure, Dragon Quest III featured an even more open-world experience. It also allowed the player to freely swap characters in and out of their party and introduced the day/night cycle in which certain items, characters, and quests are only accessible at specific times of the day.

Dragon Quest III features a class system, in which each character has a certain class. At the start of the game, the player begins as a single male or female hero but is able to recruit members at the local tavern. While the Hero always keeps the Hero class, the other characters can choose to be any of the following of either gender: Soldier (Warrior in the GBC version), Fighter, Pilgrim (Cleric), Wizard (Mage), Merchant (Dealer), Goof-Off (Jester), Sage, and Thief which was available only in the later versions. The choice of class greatly affects the character's stats and spells he or she can learn. Furthermore, upon reaching experience Level 20, a character has the option of changing classes at the temple of Dhama, found halfway through the game. A character who changes classes has their stats halved and restarts at experience Level 1, retaining their spells and, in the remakes, their personality. This allows a player to create a character that knows Wizard spells but has the defense of a Soldier. Unlike most Dragon Quest parties, aside from the Hero, the party is not made up of characters involved in the story. Although only four characters can be in the party at a time, extra members of the party can be kept at the tavern, allowing room for new recruits. Another innovation is an arena where the player can place bets on the outcome of monster battles in order to win more gold.

In the remakes, after selecting a character, the player can change the character's starting abilities with five magical seeds, given at the tavern. Also, each character has a personality trait which affects the growth rate of their abilities. The Hero's personality is determined by the player's choices and actions during a dream sequence at the start of the game, while other characters' personalities are determined by their status at the end of the character generation process. Most personalities are available to both male and female characters, while a few are exclusive to male or female characters. A character's personality can be temporarily changed by equipping certain accessories, or permanently changed by using certain consumable books.

The game starts in the castle town of Aliahan. Like the rest of the Dragon Quest worlds, this castle is set in a medieval-like time period, complete with knights and magicians. The party explores several caves, ruins, and castles during the adventure. The geography of Dragon Quest III largely corresponds to the actual geography of Earth, and many towns correspond to their real-world cultures, including "Romaly" for Rome, "Portoga" for Portugal, "Assaram" near present-day Iraq (derived from "as-salamu alaykum"), "Jipang" for Japan (where the hero fights Yamata no Orochi) and even a "New Town" in eastern North America that experiences a revolution against an overbearing ruler (derived from the American Revolution against the United Kingdom in 1776).

Dragon Quest III is set many years before the original Dragon Warrior in a world separate from the first two games. A wicked fiend named Baramos threatens to destroy the world. The story revolves around the Hero, son or daughter (the player can choose to be either male or female, with few gameplay changes) of the legendary warrior Ortega. On their sixteenth birthday, the Hero is summoned to the castle and is given by the King of Aliahan the challenge to rid the world of the evil archfiend Baramos, which Ortega attempted in the past but seemingly perished in a volcano. The Hero then is able to recruit up to three traveling companions to help fight Baramos.

The Hero leaves their home country of Aliahan to travel the world and complete their father's quest to defeat Baramos. A major portion of the adventure is the quest to acquire the last two of the three keys needed to open doors throughout the game. After saving two people of the town of Baharata from the rogue Kandar and stealing back the King of Romaly's crown, the Hero receives Black Pepper, which they then trade for a sailing ship at Portoga. With the ship, the Hero acquires the Final Key and the six mystical orbs which are used to revive the legendary bird Ramia. Ramia allows the Hero and their party to travel to Baramos' castle, which is surrounded by mountains.