The Eiger (Swiss Standard German pronunciation: [ˈaɪɡər] ) is a 3,967-metre (13,015 ft) mountain of the Bernese Alps , overlooking Grindelwald and Lauterbrunnen in the Bernese Oberland of Switzerland, just north of the main watershed and border with Valais. It is the easternmost peak of a ridge crest that extends across the Mönch to the Jungfrau at 4,158 m (13,642 ft), constituting one of the most emblematic sights of the Swiss Alps. While the northern side of the mountain rises more than 3,000 m (10,000 ft) above the two valleys of Grindelwald and Lauterbrunnen, the southern side faces the large glaciers of the Jungfrau-Aletsch area, the most glaciated region in the Alps. The most notable feature of the Eiger is its nearly 1,800-metre-high (5,900 ft) north face of rock and ice, named Eiger-Nordwand, Eigerwand or just Nordwand, which is the biggest north face in the Alps. This substantial face towers over the resort of Kleine Scheidegg at its base, on the eponymous pass connecting the two valleys.

The first ascent of the Eiger was made by Swiss guides Christian Almer and Peter Bohren and Irishman Charles Barrington, who climbed the west flank on August 11, 1858.