| Monaughty House | |
| Map Relief: | yes |
| Coordinates: | 52.31°N -3.119°W |
| Location: | Llangunllo, Powys, Wales |
| Built: | c.1565 |
| Architecture: | Vernacular |
| Governing Body: | Privately owned |
| Designation1: | Grade I listed building |
| Designation1 Offname: | Monaughty House |
| Designation1 Date: | 24 October 1951 |
| Designation1 Number: | 9126 |
Monaughty House (or Mynachdy, Welsh for 'Monastery') stands in the community of Llangunllo, Powys, Wales. Dating from c. 1565, it is one of the oldest stone-built houses in the county and a Grade I listed building.
Monaughty House stands south-east of the village of Llangunllo in the eastern part of Powys, close to the border with England. The house was built in the mid-16th century for the Price family, local landowners who served as high sheriffs and members of Parliament for the historic county of Radnorshire in the 16th and 17th centuries. James Price, the builder of the house, was a beneficiary of the dissolution of the monasteries, Monaughty was built on the site of a grange belonging to Cwmhir Abbey. Peter Smith notes that further work was undertaken in the 1630s, including the creation of a staircase leading off the central hall.
Monaughty is a private house and is not open to the public. In the 20th–21st centuries, its owners have undertaken an extensive programme of restoration.
Monaughty House was built to a traditional U-plan, with a central hall and two projecting wings; it is one of the earliest houses in Powys to have been built in stone. Above the hall, and accessed via a stair turret, is an "impressively large" great chamber. Robert Scourfield and Richard Haslam, in their Powys volume in the Buildings of Wales series, describe it as "one of the best houses of its type in Wales". The interior contains plasterwork with the coat of arms of Elizabeth I. Monaughty House is a Grade I listed building.