A rumor (American English), or rumour (British English; see spelling differences; derived from Latin rumorem 'noise'), is "a tall tale of explanations of events circulating from person to person and pertaining to an object, event, or issue in public concern."

In the social sciences, a rumor involves a form of a statement whose veracity is not quickly or ever confirmed. In addition, some scholars have identified rumor as a subset of propaganda. Sociology, psychology, and communication studies have widely varying definitions of rumor.

Rumors are also often discussed with regard to misinformation and disinformation (the former often seen as simply false and the latter seen as deliberately false, though usually from a government source given to the media or a foreign government).