Rannoch Moor is a large expanse of around 30 square miles (78 km²) of boggy moorland to the west of Loch Rannoch, in the Watsonian Vice County of Mid Perth and the County of Perthshire, in Scotland.

It is notable for its wildlife, and was freqently visited by Horace Donisthorpe who collected many unusual species of ants on the moor and surrounding hilly ground. Today it is still one of the few remaining habitats for Formica exsecta, the narrow-headed ant, although recent surveys have failed to produce any sign of Formica pratensis, which Donisthorpe all recorded in the area in the early part of the 20th century.