Since the demise of the man believed to be Britannia's most wicked emperor one year ago, the world has enjoyed an unprecedented peace under the guidance of the United Federation of Nations. However, this fragile calm is shattered when armed militants successfully kidnap former princess Nunnally vi Britannia and Suzaku Kururugi, the chief advisor of the Black Knights, sparking an international crisis.

The powerful and untrustworthy Kingdom of Zilkhstan is accused of orchestrating their capture. To investigate, world authorities send Kallen Stadtfeld and her associates on a covert operation into the country. There, they encounter the immortal witch C.C., who is on a mission to complete the resurrection of the man responsible for the greatest revolution in history—a legend who will rise up, take command, and save the world from peril once again.

Code Geass: Fukkatsu no Lelouch is considered an alternative ending to the Code Geass series. It is not a sequel to Code Geass: Hangyaku no Lelouch R2.

The film released across Japan in 120 theatres on February 9, 2019. It saw two pre-screenings in Sydney, Australia at the Madman Anime Festival on March 17, and at Sakura-Con on April 20. It also saw one pre-screening in the United States at the Boston Anime convention on April 20. The film screened in North America on May 5 (subtitled) and on May 7–8 (dubbed).