Blackadder House was an estate and stately house near the village of Allanton, in Berwickshire, Scotland. It was built on the site of the earlier Blackadder Castle. The house was vandalised by troops in World War I. Since there was no money to repair it, the house was demolished around 1925.

Allanton is a small village in the Scottish Borders region of Scotland. Historically part of Berwickshire, for many years it was part of the estate of Blackadder House, which was demolished around 1925.