Black Law is a hill in the Manor Hills, part of the Southern Uplands of Scotland. One of the more remote Donalds, it does not easily combine into a round with other hills in the area and requires traversing rough terrain to reach the top. Common ascents are as part of an extended Dun Rig Horseshoe to the north-east, from the south at the Megget Reservoir or, most easily, from the Manor Valley itself.