Ultima is a series of open world fantasy role-playing video games from Origin Systems Ultima was created by Richard Garriott. Electronic Arts has owned the brand since 1992. The series sold over 2 million copies by 1997.

A significant series in computer game history, it is considered, alongside Wizardry and Might and Magic, to be one of the norm-establishers of the computer role-playing game genre. Several games of the series are considered seminal entries in their genre, and each installment introduced new innovations which then were widely copied by other games.

The games take place for the most part in a world called Britannia; the constantly recurring hero is the Avatar, first named so in Ultima IV. They are primarily within the scope of fantasy fiction but contain science fiction elements as well.