The Witenagemot or the Witena gemot, also known as the Witan (more properly the title of its members) was a political institution in Anglo-Saxon England which operated from before the 7th century until the 11th century. The name witenagemot derives from the Old English for "meeting of wise men." The Witenagemot functioned as a national assembly whose primary function was advisory to the king and whose membership was composed of the most important noblemen in England, both ecclesiastic and secular. The institution represents an aristocratic evolution of the ancient Germanic folkmoots. In England, by the 7th century, these ancient folkmoots had developed into convocations of the land's most powerful and important people, including ealdormen, thegns, archbishops, bishops and abbots, to discuss matters of both national and local importance.

Although ostensibly under the thumb of the king, the witan is noted as having the singular power to ceosan to cyninge, 'to choose the king'. Nevertheless, at least until the eleventh century, royal succession generally followed the ordinary system of primogeniture. In addition to having a role in the 'election' of English kings, the witenagemots had the power to depose an unpopular king. However, there are only two occasions where this occurred, in 757 and 774 with the depositions of kings Sigeberht of Wessex and Alhred of Northumbria respectively.

In the year 1013 King Ethelred the Unready fled the country from Sveinn Forkbeard, who proclaimed himself king. Within a year, Sveinn died and Ethelred was called back to England by the witan. According to the Anglo-Saxon Chronicle, the witan would only receive him back under the condition that he promise to rule better than he had. Ethelred did so, and was reinstated as king of England.