Ashburnham House is an extended seventeenth-century house on Little Dean's Yard in Westminster, London, United Kingdom, and since 1882 has been part of Westminster School. It is occasionally open to the public, when its staircase and front drawing room in particular can be seen to be superb.
The current Ashburnham House was built by Inigo Jones or his pupil John Webb around the time of the Restoration, as a London seat for the family that became the Earls of Ashburnham. It incorporates remains of the medieval Prior's House, and its garden is the site of the monks' refectory, and some of the earliest sittings of the House of Commons: one instance in which they met in the refectory was to impeach Piers Gaveston, in the time of Edward II.
The library of historic manuscripts was kept here, to which was later added the old King's or Regius Library: the books and manuscripts now form the heart of the British Library. A fire in Ashburnham House on 23 October 1731 damaged much of the library; a contemporary records the librarian, Dr. Bentley, leaping from a window with the priceless Codex Alexandrinus under one arm. The manuscript of Beowulf was damaged, and reported in The Gentleman's Magazine.
The House was the object of a scandalous legal and parliamentary battle between the canons of Westminster Abbey and Westminster School for twenty years after the Clarendon Commission recommended that Westminster Abbey surrender it to the School upon the demise of its current occupant, the redoubtable sub-dean The Reverend Lord John Thynne, who lived there with his equally formidable wife and nine children. The Dean and Chapter attempted to evade their obligations under the Public Schools Act, by purportedly using their control of the School's Governing Body to sell out the school's statutory right for the benefit of the Canons. Even after this was defeated by a debate in Parliament, Lord John survived until 1881, once surprising the headmaster looking over his garden wall with the words "Not Dead Yet, Dr. Gow!"
The house was the original location of Westminster's first day-house, also known as Ashburnham House, from when it was founded until it moved in 1951 to 5 Dean's Yard.
During the Second World War, the library was used as a communications station for the Royal Air Force, the ground floor as the American officers' "Churchill Club", and a senior conference facility for secret military purposes.
In 1969, it was used as one of the locations for the film The Magic Christian.