Westminster Hall is a large medieval great hall which is part of the Palace of Westminster in London, England. It was erected in 1097 for William II, at which point it was the largest hall in Europe. The building has had various functions over the years, including being used for judicial purposes from the twelfth to the nineteenth centuries. When a joint address is given to the two chambers of the UK Parliament, the House of Commons and House of Lords, the hall is typically the venue. It was also used to host coronation banquets until 1821, and since the twentieth century has been the usual venue for the lyings in state of state and ceremonial funerals.

A great hall is the main room of a royal palace, castle or a large manor house or hall house in the Middle Ages, and continued to be built in the country houses of the 16th and early 17th centuries, although by then the family used the great chamber for eating and relaxing. At that time the word "great" simply meant big and had not acquired its modern connotations of excellence. In the medieval period, the room would simply have been referred to as the "hall" unless the building also had a secondary hall, but the term "great hall" has been predominant for surviving rooms of this type for several centuries, to distinguish them from the different type of hall found in post-medieval houses. Great halls were found especially in France, England and Scotland, but similar rooms were also found in some other European countries.