Oberaletsch Glacier, Alpine glacier in Valais, Switzerland

Oberaletsch Glacier is a valley glacier on the south side of the Bernese Alps in Valais, Switzerland. It has two source branches of similar size: one starts as a steep hanging glacier on the southwest flank of the Aletschhorn at about 3,700 m, the other is the Beich Glacier on the east slope of the Lötschentaler Breithorn. They join and flow southeast between the Sparrhorn and Grosses Fusshorn, ending at about 2,150 m.

This glacier once formed part of the larger Aletsch system during the 19th century but gradually separated over time. The disconnection occurred as regional ice masses responded to shifting climate conditions.

The Oberaletschhütte, a Swiss Alpine Club hut at 2,640 m above the junction of the Beich and Oberaletsch glaciers, was long reached only across the ice. Since July 2005 a panorama path along the southwest flank of the Fusshörner gives a glacier-free approach, about 4 to 5 hours from the Belalp mountain station.

Marked hiking trails from Belalp provide access to the ice field at varying difficulty levels suited to different abilities. A staffed mountain hut at 2,640 meters (8,660 feet) offers shelter and supplies for visitors exploring the area.

During the Little Ice Age in the mid-19th century, the Oberaletsch Glacier was joined to the Great Aletsch Glacier through the ice-filled Oberaletsch gorge; this link broke around 1878. A second, flat tongue lobe reached over a ridge onto the Obflühgand until 1906.