Plas Uchaf (English: Upper Hall) is a 15th-century cruck-and-aisle-truss hall house, 1.5 miles (2.4 km) south-west of Corwen, Denbighshire, Wales and 1 mile (1.6 km) north of Cynwyd.

Its excellent workmanship indicates a house originally of considerable importance; it has been described as "of palatial significance".

The roof structure is substantial, of paired cruck beams with additional horizontal, vertical and diagonal bracing.

[6] In the 16th century the hall was divided horizontally by the addition of an inserted floor supported by moulded cross beams.

[3] Peter Smith and Ffrangcon Lloyd drew attention to the building in 1964,[3] and it was eventually taken on and restored by the Landmark Trust.