The Lötschberg is an Alpine mountain massif, usually associated with a major, historically important transit axis of the Alps in Switzerland with, at its core, the Lötschen Pass (German: Lötschenpass, Swiss German: Lötschepass). The mountain pass, which culminates at nearly 2,700 metres above sea level, are part of the eastern Bernese Alps , whose main crest straddles the border between the cantons of Bern and Valais . The valleys concerned by the Lötschberg are those of the Kander in the Berner Oberland, with Kandersteg at the head of it, and a secluded side-valley of the Upper Valais, the Lötschental , with Ferden at the valley's entrance and at the bottom of the pass.

Although the Lötschberg is one of the main north-south axes through the Alps, it is not on the main chain of the Alps, the Pennine Alps , further south, making up the main water divide. As a main north-south axis through the Alps, the Lötschberg is thus completed by the Simplon, between Brig and Domodossola in Italy. The Lötschberg alone constitutes an important shortcut from the Swiss Plateau to the Upper Valais, the alternative route involving a long detour via the lower Rhone Valley (Monthey ) around the western end of the Bernese Alps.