Tarfessock is a hill in the Range of the Awful Hand range in the Galloway Hills, part of the Southern Uplands of Scotland. A craggy hill, it is the lowest Donald in the range, being completely obscured by Kirriereoch Hill when viewed from the Merrick. A nearby south top is dotted with a series of lochans. A farmhouse of the same name is located to the west, which along with the hill was at one time the property of the Marquess of Ailsa.