Beinn a' Bheithir (Scottish Gaelic for ''Mountain of the Thunderbolt'') is a mountain lying to the south of Ballachulish, on the south side of Loch Leven in the Scottish Highlands. It boasts two Munro summits: the higher peak Sgorr Dhearg (]) lies about east of Sgorr Dhonuill (Sgurr Dhòmhnaill).