A legend is a genre of folklore that consists of a narrative featuring human actions, believed or perceived to have taken place in human history. Narratives in this genre may demonstrate human values, and possess certain qualities that give the tale verisimilitude. Legend, for its active and passive participants may include miracles. Legends may be transformed over time to keep them fresh and vital.

Many legends operate within the realm of uncertainty, never being entirely believed by the participants, but also never being resolutely doubted. Legends are sometimes distinguished from myths in that they concern human beings as the main characters rather than gods, and sometimes in that they have some sort of historical basis whereas myths generally do not. The Brothers Grimm defined legend as "folktale historically grounded". A by-product of the "concern with human beings" is the long list of legendary creatures, leaving no "resolute doubt" that legends are "historically grounded."

A modern folklorist's professional definition of legend was proposed by Timothy R. Tangherlini in 1990:

Legend, typically, is a short (mono-) episodic, traditional, highly ecotypified historicized narrative performed in a conversational mode, reflecting on a psychological level a symbolic representation of folk belief and collective experiences and serving as a reaffirmation of commonly held values of the group to whose tradition it belongs.