Tintagel Old Post Office is a 14th-century stone house, built to the plan of a medieval manor house, situated in Tintagel, Cornwall, United Kingdom. The house, and its surrounding cottage garden, are in the ownership of the National Trust, and the building is Grade I listed. The name dates from the Victorian period when it briefly held a licence to be the letter receiving station for the district. The Trust has restored it to this condition. It was among the early acquisitions of the Trust (1903) and closes in the winter months.
The building was acquired by the Trust from its owner Catherine Eliza Johns (died 1925) who had employed the architect Detmar Blow to renovate it in 1896. (Blow was also responsible for some buildings at Treknow in the 1890s.) Catherine Johns had bought it in 1895 to prevent its demolition. She and a number of other artists then raised money to enable the National Trust to buy it from her.
The house was built in c.1380 as a medieval thatched house of three rooms with a through-passage. The building would originally have been a single storey dwelling, open to the roof, and would have housed livestock in the northern partition. A central hearth in the hall would have offered warmth and provided smoke that would seep through the thatch above, killing off woodworm and preserving the wooden frames.
Modified since the medieval period, the main phases of re-development took place during the 16th and 17th centuries: local brown slate was used in place of thatch for the roof, timber panelling was replaced with stone and a fireplace and central chimney stack were also added.