An Teallach is a mountain in Scotland. It lies to the southwest of Dundonnell and overlooks Little Loch Broom, in an area often nicknamed the "great wilderness". An Teallach means 'The Anvil' or 'The Forge' in Scottish Gaelic; although most scholars claim the latter is most correct as the mountain's name refers more to the colour of the terrain in certain lighting conditions, rather than shape.

The mountain is mostly made of Torridonian sandstone. Like the peaks around Torridon (for which the rock is named), An Teallach has terraced sides riven with steep gullies and a sharp rocky summit crest at Sgùrr Fiona. The steepest section, known as Corrag Bhuidhe, rises above Loch Toll an Lochain. Corrag Bhuidhe's most spectacular feature is an overhanging An Teallach is a complex mountain massif, with ten distinct summits over 3,000 feet (914.4 m). From 1891 to 1981, only the highest of these, Bidean a' Ghlas Thuill, had the status of a Munro – a separate mountain over 3,000 feet. In 1981 the Scottish Mountaineering Club granted Munro status to Sgùrr Fiona, in recognition of its considerable topographic prominence (150 m) and distinct naturepinnacle known as Lord Berkeley's Seat.