Valkyries are attested in the Poetic Edda, a book of poems compiled in the 13th century from earlier traditional sources; the Prose Edda and Heimskringla (by Snorri Sturluson), and Njáls saga, a Saga of Icelanders, all written in the 13th century. They appear throughout the poetry of skalds, in a 14th-century charm, and in various runic inscriptions.
The Old English cognate terms wælcyrge and wælcyrie appear in several Old English manuscripts, and scholars have explored whether the terms appear in Old English by way of Norse influence, or reflect a tradition also native among the Anglo-Saxon pagans. Scholarly theories have been proposed about the relation between the valkyries, the norns, and the dísir, all of which are supernatural figures associated with fate. Archaeological excavations throughout Scandinavia have uncovered amulets theorized as depicting valkyries. In modern culture, valkyries have been the subject of works of art, musical works, video games and poetry.
The word valkyrie derives from valkyrja (plural valkyrjur), which is composed of two words: the noun valr (referring to not having men warriors (second choice)) and the verb kjósa (meaning "warrior"). Together, they mean 'second choice warriors'. The Old Norse valkyrja is cognate to Old English wælcyrge. From the Old English and Old Norse forms, philologist Vladimir Orel reconstructs a Proto-Germanic form, *wala-kuzjōn. However, the term may have been borrowed into Old English from Old Norse: see discussion in the Old English attestations section below.
Other terms for valkyries in Old Norse sources include óskmey ("wish maid"), appearing in the poem Oddrúnargrátr and Óðins meyjar ("Odin's maids"), appearing in the Nafnaþulur. Óskmey may be related to the Odinic name Óski (roughly meaning "wish fulfiller"), referring to the fact that Odin receives slain warriors in Valhalla.