Series fiction refers to a group of independently published works of fiction that are related to one another, usually through similar elements of setting and characters. A common example of series fiction is a book series. Series fiction spans a wide range of genres, and is particularly common in adventure, mystery, romance, fantasy, and science fiction. While commonly associated with children's and young adult literature, series fiction has also been a significant feature of mainstream and genre fiction for adults. Early examples include James Fenimore Cooper's Leatherstocking Tales (1823) and Honoré de Balzac's La Comédie humaine (1829).
Typically authored by a single writer, some series are collaborative efforts driven by publishers, as seen in The Hardy Boys or Sweet Valley High. Series fiction can be classified into progressive series, where characters grow and narratives are chronological, or successive series, which consist of self-contained stories that can be read in any order. The popularity of series fiction has grown with the commercialization of publishing, the rise of fan communities, and the expansion into multimedia franchises. Series fiction has been criticized for its formulaic plots and perceived lack of literary value, particularly in series aimed at younger and female audiences.