Villanelle is a formal poem of nineteen lines arranged into five tercets followed by a concluding quatrain that ends with a rhyming couplet; it also has a complex rhyme and repetition scheme, in which the entire first and third lines of the first tercet are alternating repeated as the third lines of each subsequent tercet, until they appear as the final rhyming couplet.

The villanelle form originated in French poetry. One of the most well-known English villanelles is “Do not go gentle into that good night,” by Dylan Thomas.

The villanelle has been noted as a form that frequently treats the subject of obsessions, and one which appeals to outsiders; its defining feature of repetition prevents it from having a conventional tone.

Villanelles appears in Modern poetry. In his 1914 novel A Portrait of the Artist as a Young Man, James Joyce includes a villanelle written by his protagonist Stephen Dedalus.

William Empson revived the villanelle
more greatly in the 1930s, and his contemporaries and friends W. H. Auden. Theodore Roethke and Sylvia Plath wrote villanelles in the 1950s and 1960s,and Elizabeth Bishop wrote a particularly famous and influential villanelle, "One Art," in 1976. The villanelle attained a remarkable level of popularity in the 1980s and 1990s with the rise of the New Formalism.