The Codex Regius of the Poetic Edda, GKS 2365 4to, is widely regarded as the most remarkable of all old Icelandic manuscripts.

It includes mythological poems that are important sources for the world view and religious beliefs of the Scandinavians prior to their conversion to Christianity; and also poems on heroes who were famous among all the Germanic peoples during the Viking Age and even earlier. Many of the poems in the book are not preserved in any other medieval source, and not one of them is preserved in a manuscript of the same age or older.

The present edition consists of a diplomatic transcription of the Codex Regius text, and three essays on important aspects of the manuscript. It also features an online electronic edition in the Editiones Arnamagnæanæ Series Electronicæ, with digital photographs (both black-and-white and in color), an XML-tagged electronic text, and a lemmatized concordance based on the electronic text.

Editors are: Guðvarður Már Gunnlaugsson, Haraldur Bernharðsson and Vésteinn Ólason.