Abstract: Fan fiction, as this entry considers it, is unauthorized, noncommercialized writing that takes as its starting point in-copyright texts but tells new stories, or stories from new perspectives, with recognizable elements of those texts. It is often used as an example of ‘user-generated content’ that raises copyright questions, given the expansion of copyright to cover more than just close reproductions. Most commentary on fan fiction concludes that it is likely to constitute a fair use under US law, though there is substantially less scholarship on fan fiction under the copyright laws of other countries.