The witan (lit. 'wise men') was the king's council in the Anglo-Saxon government of England from before the 7th century until the 11th century. It comprised important noblemen, including ealdormen, thegns, and bishops. Meetings of the witan were sometimes called the witenagemot.

Its primary function was to advise the king on legislation, judicial cases, land transfers, and other matters of national importance. The witan may have elected new kings from among members of the ruling dynasty. After the Norman Conquest in 1066, these roles were performed by a similar council known as the curia regis.

The witan is considered an ancestor of the Parliament of England. Before the 20th century, historians thought it had been a proto-parliament, an institution that was both democratic and representative. In the 20th century, historical interpretation emphasised the witan's ad hoc and essentially royal nature.

The Old English word witan (lit. 'wise men') described the counsellors of Anglo-Saxon kings. At the same time, the word could also refer to other kinds of counsellors, such as the witan of a shire court. Wulfstan II, Archbishop of York (1002–1023), wrote in his Institutes of Polity that "it is incumbent on bishops, that venerable 'witan' always travel with them, and dwell with them, at least of the priesthood; that they may consult with them ... and who may be their counsellors at every time." A contemporary account of a dispute over an estate in Middlesex in the 950s refers to a decision of the Myrcna witan ('Mercian witan').

The most common Old English term for a meeting of the witan is gemot, sometimes expanded as micel gemot ('great assembly'). Writers of Latin texts used conventus or magnum sapientium conventus (lit. 'great assembly of wise men'). Modern scholars use witenagemot ('assembly of counsellors') as a technical term, but historian John Maddicott noted its rarity in the 11th century with only nine pre-Conquest examples, mainly in the crisis of 1051–1052. Patrick Wormald was also cautious, describing it as "a word always rare and unattested before 1035".

The origins of the witan lie in the practice of Germanic kings seeking the advice of their great men. This practice survived within the many Anglo-Saxon kingdoms established after the end of Roman rule in Britain. Maddicott writes that these early "royal assemblies lacked the institutional qualities of regularity, formality of structure, and a distinctive agenda" seen in later assemblies. They were also distinctly local. The first recorded act of a witenagemot was the law code of King Æthelberht of Kent c. 600, the earliest document which survives in sustained Old English prose.

Before the 9th century, only church councils, such as the Council of Hertford in 672, transcended the boundaries of individual kingdoms. With the unification of England in the 10th century, the witan acquired a national scope for the first time.

According to historian Bryce Lyon, the witan "was an amoebic sort of organization with no definite composition or function". It does appear, however, that an indispensable requirement was the presence of leading secular and ecclesiastical magnates. Kings issued royal charters at meetings of the witan, and historians use the witness lists to these charters to discover who attended. About 2,000 charters and 40 law codes attest to the workings of around 300 recorded witan meetings. Typically, scribes listed witnesses in hierarchical order, with the king listed first, followed by: