The green-tailed sunbird (Aethopyga nipalensis) or Nepal yellow-backed sunbird is a species of bird in the Nectariniidae family. It ranges across the northern regions of the Indian subcontinent, stretching eastwards into parts of Southeast Asia. It is found in Bangladesh, Bhutan, northeast India, Laos, Myanmar, Nepal, Thailand, Tibet and Vietnam. Its natural habitats are temperate forests and subtropical or tropical moist montane forests. In southeast Szechwan and Yunnan, it lives in open mountain woods with moss-covered trees, from 1825 to 3350 meters elevation.