Engilchek Glacier (Kyrgyz: Эңилчек, Russian: Энильчек - Enilchek, also Иныльчек - Inylchek) is a glacier in the Central Tian Shan Mountains of Issyk Kul Province, northeastern Kyrgyzstan.
Its snout is 50 km east of the village of Engilchek. The South Inylchek Glacier ranks as the sixth longest non-polar glacier in the world and is the largest and fastest moving glacier in Kyrgyzstan. The main glacier has two arms, the North and South Engilchek Glaciers. The latter is longer and provides an overall length of 60.5 kilometres (38 mi). with an area of 17.2 square kilometres (7 sq mi) and an ice thickness of roughly 150–200 m in the bottom parts.
The glacier stems from the Chinese-Kazakh-Kyrgyz massif of Khan Tengri and Pik Pobedy and the upper part of the glacier falls in all three countries. Meltwater from the glacier feeds a tributary of the Aksu River, which crosses the Chinese border into the Tarim Basin. Water from this glacier also feeds the seasonal glacial Lake Merzbacher which ultimately flows into the Engilchek River.