Barmoor Castle ( grid reference NT99723988) is a privately owned 19th-century country house built on an ancient site in Northumberland.

After the Norman Conquest the Manor of Barmoor was granted to the Muschamp family who built a tower house on the site.

After 1702 the estate changed hands several times until in 1791 it was acquired by inheritance by Francis Hurt Sitwell.

The Sitwells engaged architect John Paterson of Edinburgh and in 1801 built the present substantial castellated Gothic revival mansion on the site of and incorporating some existing stonework of the old house.

[1] The present owner occupiers, the Lamb family, acquired the house and 200 acres (0.81 km2) in the 1980s from where they operate a caravan and holiday park.