Daer Reservoir is a man-made waterbody created by the damming of the Daer Water, a tributary of the River Clyde in the Southern Uplands of Scotland. It lies within the Lowther Hills in South Lanarkshire. A minor public road leaving the A702 follows the Daer Water south to the dam and then continues along the western margin of the reservoir as far as Kirkhope. The reservoir was officially opened by HM Queen Elizabeth II in 1956 to supply water to the Scottish Central Belt.