Sir Gawain and the Green Knight is a late 14th-century chivalric romance in Middle English alliterative verse. The author is unknown; the title was given centuries later. It is one of the best-known Arthurian stories, with its plot combining two types of folk motifs: the beheading game, and the exchange of winnings. Written in stanzas of alliterative verse, each of which ends in a rhyming bob and wheel, it draws on Welsh, Irish, and English stories, as well as the French chivalric tradition. It is an important example of a chivalric romance, which typically involves a hero who goes on a quest which tests his prowess. It remains popular in modern English renderings from J. R. R. Tolkien, Simon Armitage, and others, as well as through film and stage adaptations.

As a literary genre, the chivalric romance is a type of prose and verse narrative that was popular in the noble courts of high medieval and early modern Europe. They were fantastic stories about marvel-filled adventures, often of a chivalric knight-errant portrayed as having heroic qualities, who goes on a quest. It developed further from the epics as time went on; in particular, "the emphasis on love and courtly manners distinguishes it from the chanson de geste and other kinds of epic, in which masculine military heroism predominates."