Ultima IX: Ascension is a 1999 role-playing video game developed by Origin Systems and published by Electronic Arts for Microsoft Windows. It is the ninth and final main installment of the Ultima series.

It takes place after the Avatar's escape from Pagan, where he is transported back to Britannia for one final battle with the Guardian, who is increasingly ruining the physical and moral fabric of that land by the use of eight columns. The Avatar must fight his way to the runes of virtue found in each of the columns, and cleanse them in the shrines of Virtue, then face off against the Guardian himself.

The game received mixed reviews from critics, with significant criticism on its lack of polish and disregard for previous installments in the series, though the gameplay received praise.

A difference from previous Ultima games is that in Ultima IX the player has less control of what path to take in the game. Most areas of Britannia are blocked off until specific tasks are completed, reducing the amount of initial exploration available to the player.

The game world is rendered in a detailed and seamless manner, but Britannia is much smaller in overall area than previous games. For example, Britain, the largest city of Britannia, consists of only a few buildings.

In the beginning of Ultima IX, the Avatar had somehow returned to Earth for an unspecified amount of time before getting back to Britannia. The game starts just after the end of Ultima VIII, in which the Avatar is transported to a Guardian-controlled Britannia. He arrives in Britannia on a mountain overlooking the Guardian's keep in Terfin. The Avatar is transported to Stonegate by Hawkwind the Seer (from Ultima IV), who informs him that great columns have appeared throughout the land, and their malignant influence has caused plagues, famine, and other natural disasters. Under their power, the people of Britannia have twisted the Virtues into mockeries of their true meaning. The Guardian is helped by Lord Blackthorn, who leads the Wyrmguards and forces the people to obey the Guardian.

As the quest progresses, the Avatar learns that the Guardian has stolen the Runes of the Virtues and twisted them into the glyphs that form the heart of each of the columns. Most of the game consists of traveling through the dungeons to recover the glyphs and visiting the Shrines of the Virtues to meditate and cleanse them. Eventually, it is revealed that the Guardian is nothing other than the dark half of the Avatar himself, and the only way to save Britannia is for the Avatar to ascend to a higher plane, taking the Guardian with him. The player is able to accomplish this via an Armageddon spell cast behind a Barrier of Life, which takes the Avatar and the Guardian to a higher plane out of Britannia.

Origin Systems released a number of preview video clips in the five years between the original release of Ultima VIII and the final release of Ultima IX in December 1999, first in the Ultima Collection and intermittently in between. These screenshots and clips pointed to a totally different plot from the released version, which many longtime fans of the Ultima saga agreed was unsatisfying and unrewarding.^{[citation needed]}