Stac Pollaidh is a mountain in the Northwest Highlands of Scotland. The peak displays a rocky crest of Torridonian sandstone, with many pinnacles and steep gullies. The ridge was exposed to weathering as a nunatak above the ice sheet during the last Ice Age, while the ice flow carved and scoured the smooth sides of the mountain.
The modern Gaelic name is a recent invention. The peak is named on the first edition Ordnance Survey maps simply as "An Stac" and on later maps as "Stac Polly". The "Polly" element is of Norse origin, derived from "Pollå" meaning "pool river". Due to its relatively low height of just over 2000 feet, fine views and ease of access from a road it has become a very popular peak to climb. It also provides some fine scrambling in the traverse of the summit ridge, including one bad step near the final summit. Consequentially it has suffered from a great deal of erosion, leading to Scottish Natural Heritage constructing a large path.