Plas Mynach is a large country house in Barmouth, Gwynedd, Wales.

It is designated by Cadw as a Grade II* listed building, and stands in a prominent position overlooking the sea.

[1] Its most distinctive features are a low spreading tower with a stair turret and stepped gables.

[1] Internally "the hall, staircase and landing provide a classic example of Douglas's domestic joinery".

[3] The description in the listing refers to it as "one of the more important country houses by John Douglas, in an apparently little-altered condition".