A stock character is a fictional character based on a common literary or social stereotype. Stock characters rely heavily on cultural types or names for their personality, manner of speech, and other characteristics. In their most general form, stock characters are related to literary archetypes, but they are often more narrowly defined. Stock characters are a key component of genre fiction, providing relationships and interactions that people familiar with the genre will recognize immediately. Stock characters make easy targets for parody, which will likely exaggerate any stereotypes associated with these characters.

By the loosest definition, stock characters have been around ever since the tragedy of Aeschylus, Sophocles, and Euripides, being based upon the traits of mythological characters. Although mythological characters are not representations of real people, they are a group that would have been recognizable to ancient audiences, and even back then, tended to fall into well-established group types. For example, Hephaestus, Hermes, and Prometheus represented the fool character as "jesters to the gods."