The Yumthang Valley or Sikkim Valley of Flowers sanctuary, is a nature sanctuary with river, hot springs, yaks and grazing pasture on rolling meadows surrounded by the Himalayan mountains in the North Sikkim district of Sikkim state in India. It is at an elevation of 3,564 metres (11,693 ft) above msl at a distance of 150 kilometres (93 mi) from the state capital Gangtok.

It is popularly known as ‘Valley of Flowers and is home to the Shingba Rhododendron Sanctuary, which has over twenty-four species of the rhododendron, the state flower. The flowering season is from late February and to mid June, when countless flowers bloom to carpet the valley in multicolored hues of rainbow.[6] A tributary of the river Teesta flows past the valley and the town of Lachung, the nearest inhabited centre. Yumthang is closed between December and March due to heavy snowfall. There is also a hot spring in the valley.

A forest rest house is the only permanent residence in the valley. During the spring months, the area blooms with rhododendrons, primulas, poppies, iris and other flora. During the summer months, villagers take their cattle to these heights to graze (a practice known as yaylag pastoralism). In view of increasing number of tourists, there is possibility of environmental degradation in near future Skiing is conducted in the valley.