Alpine tundra is a type of natural region or biome that does not contain trees because it is at high altitude. Alpine tundra is distinguished from arctic tundra, because alpine soils are generally better drained than arctic soils. Alpine tundra transitions to subalpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone are known as Krummholz.

Alpine tundra occurs in mountains worldwide. The flora of the alpine tundra is characterized by dwarf shrubs close to the ground. The cold climate of the alpine tundra is caused by the low air pressure, and is similar to polar climate.

Alpine tundra occurs at high enough altitude at any latitude. Portions of Montane grasslands and shrublands ecoregions worldwide include alpine tundra. Large regions of alpine tundra occur in the American Cordillera in North and South America, the Alps and Pyrenees of Europe, the Rift Mountains of Africa, and a large portion of the Tibetan Plateau.

Alpine tundra occupies high-mountain summits, slopes, and ridges above timberline. Aspect plays a role as well: the treeline often occurs at higher elevations on warmer sun-facing slopes. Because the alpine zone is present only on mountains, much of the landscape is rugged and broken, with rocky, snowcapped peaks, cliffs, and talus slopes, but also contains areas of gently rolling to almost flat topography.