The Plaine Morte Glacier (lit.: Dead Plain Glacier; ) is a glacier located at an elevation of , in the canton of Bern above Lenk and in the Valais above Crans-Montana in Switzerland. The ice field, which covers , is located below the mountain of Wildstrubel in the Bernese Alps. Its largest tongue is also called in German Rezligletscher or Rätzligletscher.
The area of Plaine Morte is easily accessible from Crans-Montana by cable car and the practice of cross-country skiing is possible throughout the year. The summit of the Pointe de la Plaine Morte offers impressive views of the Valais Alps.
A large lake formed at the eastern base of the glacier, south of the Schneehorn, at a height of 2,752 metres above sea level. The surface area of the lake is 0.11 km².