The Visio Tnugdali is a 12th-century religious text reporting the otherworldly vision of the Irish knight Tnugdalus. It was "one of the most popular and elaborate texts in the medieval genre of visionary infernal literature" and had been translated from the original Latin forty-three times into fifteen languages by the 15th century, including Icelandic and Belarusian. The work remained most popular in Germany, with ten different translations into German, and four into Dutch. With a recent resurgence of scholarly interest in Purgatory following works by Jacques Le Goff, Stephen Greenblatt and others, the vision has attracted increased academic attention.

Jacques Le Goff was a French historian and prolific author specializing in the Middle Ages, particularly the 12th and 13th centuries.