Baconsthorpe Castle is a fortified manor house close to Baconsthorpe in Norfolk. It is a grade I listed building in the care of English Heritage.

Baconsthorpe Castle was built by John Heydon in about 1460 out of flint and brick. He used the manor as a defensive base as he had many enemies because of his actions during the War of the Roses when he switched sides on a regular basis to further his personal fortune and purposes. John Heydon was a lawyer and then invested in sheep as these became profitable. The manor was built without a licence and was originally a square manor house which was then fortified. It became more elaborate the richer the family became. A moat was added and a lake built on the east side for added protection.

The early gatehouse is set into the southern wall of the courtyard. It is a three storied building designed to be a self contained defendable building. It had two small lodges on the ground floor, one for the porter and the other for a servant. The first floor housed the Heydon family with a suite of luxurious rooms. It is thought that the top floor was used as a chapel. A drawbridge crossed the moat adding to the security of the building.

The walled courtyard was later used for wool processing with converted buildings in the Tudor period. The eastern buildings had large windows so the spinners and weavers had enough light to work by. Most of the cloth was sold to the Netherlands, it was a course material softened by pounding the cloth in urine in the north west tower.

The later gatehouse was added to create an impressive entrance to the manor and to create an outer courtyard. A row of cottages sat on the eastern side and a long barn on the west side of the courtyard. The barns are still in use by the local farmer.