The Poetic Edda is the modern name for an untitled collection of Old Norse anonymous narrative poems, which is distinct from the Prose Edda written by Snorri Sturluson, although both works are seminal to the study of Old Norse poetry. Several versions of the Poetic Edda exist: especially notable is the medieval Icelandic manuscript Codex Regius, which contains 31 poems. The Codex Regius is arguably the most important extant source on Norse mythology and Germanic heroic legends. Since the early 19th century, it has had a powerful influence on Scandinavian literature, not only through its stories, but also through the visionary force and the dramatic quality of many of the poems. It has also been an inspiration for later innovations in poetic meter, particularly in Nordic languages, with its use of terse, stress-based metrical schemes that lack final rhymes, instead focusing on alliterative devices and strongly concentrated imagery. Poets who have acknowledged their debt to the Codex Regius include Vilhelm Ekelund, August Strindberg, J. R. R. Tolkien, Ezra Pound, Jorge Luis Borges, and Karin Boye.

The Codex Regius was written during the 13th century, but nothing was known of its whereabouts until 1643, when it came into the possession of Brynjólfur Sveinsson, then Bishop of Skálholt. At the time, versions of the Prose Edda were known in Iceland, but scholars speculated that there once was another Edda, an Elder Edda, which contained the pagan poems that Snorri quotes in his Prose Edda. When Codex Regius was discovered, it seemed that the speculation had proved correct, but modern scholarly research has shown that the Prose Edda was likely written first and that the two were, at most, connected by a common source.

Brynjólfur attributed the manuscript to Sæmundr the Learned, a larger-than-life 12th century Icelandic priest. Modern scholars reject that attribution, but the name Sæmundar Edda is still sometimes associated with both the Codex Regius and versions of the Poetic Edda using it as a source.

Bishop Brynjólfur sent the manuscript as a present to the Danish king, hence the Latin name Codex Regius, lit. 'Royal Book'. For centuries it was stored in the Royal Library in Copenhagen, but in 1971 it was returned to Iceland. Because air travel at the time was not entirely trustworthy with such precious cargo, it was transported by ship, accompanied by a naval escort.