The First Nowell" is of Cornish origin. Its current form was first published in Carols Ancient and Modern (1823) and Gilbert and Sandys Carols (1833), both of which were edited by William Sandys and arranged, edited and with extra lyrics written by Davies Gilbert for Hymns and Carols of God.

Nowell is an Early Modern English synonym of "Christmas" from French Noël "the Christmas season", ultimately from Latin natalis [dies] "[day] of birth".The word was regularly used in the burden of carols in the Middle Ages towards the early modern period; Sir Christèmas (Ritson Manuscript), "Nowell sing we now all and some" (Trinity Carol Roll)and "Nowel - out of youre slepe arise and wake" (Selden Carol Book) being 15th century examples.

The melody is unusual among English folk melodies in that it consists of one musical phrase repeated twice, followed by a refrain which is a variation on that phrase. All three phrases end on the third of the scale. Writing in the Journal of the Folk-Song Society in 1915, Anne Gilchrist notes it was not recorded prior to Sandys' publication. She speculated based on a set of church gallery parts discovered in Westmorland that the tune may have had its origin as a treble part to another carol "Hark, hark what news the angels bring"; her suggestion was that the treble part was passed down orally and was later remembered as the melody rather than a harmony.A conjectural reconstruction of this earlier version can be found in the New Oxford Book of Carols.

Today, "The First Nowell" is usually performed in a four-part hymn arrangement by the English composer John Stainer, first published in his Carols, New and Old in 1871