The Giétro Glacier or Giétroz Glacier (French: Glacier du Giétro) is a 4 km (2.5 mi) long valley glacier located in south-western Switzerland . The 1818 Giétro Glacier catastrophe, which led to a lake outburst flood, is one of the worst disasters in the history of the Swiss Alps .

The Giétro Glacier lies on the northern side of the Pennine Alps in the Swiss canton of Valais . It is located in the upper Bagnes Valley, south of Martigny and Verbier . The length of the glacier in 2017 was 4.45 km (2.77 mi) and its area was 5.3 km2 (2.0 sq mi).

The glacier is fed by snows from Mont Blanc de Cheilon at 3,870 m (12,700 ft) high and La Ruinette at 3,875 m (12,713 ft) high.