Metafiction is a form of fiction that emphasizes its own narrative structure in a way that inherently reminds the audience that they are reading or viewing a fictional work. Metafiction is self-conscious about language, literary form, and storytelling, and works of metafiction directly or indirectly draw attention to their status as artifacts. Metafiction is frequently used as a form of parody or a tool to undermine literary conventions and explore the relationship between literature and reality, life and art.

Although metafiction is most commonly associated with postmodern literature that developed in the mid-20th century, its use can be traced back to much earlier works of fiction, such as The Canterbury Tales (Geoffrey Chaucer, 1387), Don Quixote Part Two (Miguel de Cervantes, 1615), Chymical Wedding of Christian Rosenkreutz (Johann Valentin Andreae, 1617), The Cloud Dream of the Nine (Kim Man-jung, 1687), The Life and Opinions of Tristram Shandy, Gentleman (Laurence Sterne, 1759), Sartor Resartus (Thomas Carlyle, 1833–34), and Vanity Fair (William Makepeace Thackeray, 1847).

Metafiction became particularly prominent in the 1960s, with works such as Lost in the Funhouse by John Barth, Pale Fire by Vladimir Nabokov, "The Babysitter" and "The Magic Poker" by Robert Coover, Slaughterhouse-Five by Kurt Vonnegut, The French Lieutenant's Woman by John Fowles, The Crying of Lot 49 by Thomas Pynchon, and Willie Master's Lonesome Wife by William H. Gass.

Since the 1980s, contemporary Latino literature has an abundance of self-reflexive, metafictional works, including novels and short stories by Junot Díaz (The Brief Wondrous Life of Oscar Wao), Sandra Cisneros (Caramelo), Salvador Plascencia (The People of Paper), Carmen Maria Machado (Her Body and Other Parties), Rita Indiana (Tentacle), and Valeria Luiselli (Lost Children Archive).

Also in Latin America, but much earlier, Ecuadorian writer Pablo Palacio published his experimental novella Débora in October 1927. Some of the techniques he employed in the book include stream of consciousness and metafiction.

A prominent video game example of metafiction is The Stanley Parable, which explores video game story-telling structures and tropes, and in particular the relationship between the creator and the player, frequently breaking the fourth wall by directly commenting on it.

The term 'metafiction' was coined in 1970 by William H. Gass in his book Fiction and the Figures of Life. Gass describes the increasing use of metafiction at the time as a result of authors developing a better understanding of the medium. This new understanding of the medium led to a major change in the approach toward fiction. Theoretical issues became more prominent aspects, resulting in increased self-reflexivity and formal uncertainty. Robert Scholes expands upon Gass's theory and identifies four forms of criticism on fiction, which he refers to as formal, behavioural, structural, and philosophical criticism. Metafiction assimilates these perspectives into the fictional process, putting emphasis on one or more of these aspects.

These developments were part of a larger movement (arguably a meta referential turn) which, approximately from the 1960s onwards, was the consequence of an increasing social and cultural self-consciousness, stemming from, as Patricia Waugh puts it, "a more general cultural interest in the problem of how human beings reflect, construct and mediate their experience in the world."