The farmstead complex of Grange Farmhouse, Newcastle, Monmouthshire is a grouping of early-18th-century farm buildings. It comprises a stable, two barns, two cow houses, a shelter-shed and a poultry enclosure with a duckpond. The complex is listed Grade II*, the associated farmhouse having a separate Grade II listing.

The complex appears to have been built in two phases, from the early 18th century. The more southernly of the two barns carries a datestone inscribed "1702". The complex is on a surprisingly large scale for a relatively minor farm, but Cadw can suggest no explanation for this.

The grouping surrounds a farmyard and consists of a stable, two barns, a couple of cow houses, a shelter shed and a walled poultry enclosure with adjacent duckpond. The buildings of constructed of Old Red Sandstone rubble, a traditional material for Monmouthshire. The roofs, originally of slate, are now of corrugated iron sheeting. The complex has a Grade II* listing, its record describing is as "an impressive and exceptionally complete complex of early-18th-century farm buildings". The associated farmhouse has its own listing of Grade II.