Umphang Wildlife Sanctuary is a wildlife sanctuary in Thailand site in the Umphang District of Tak Province, northwestern Thailand. It was announced as a protected sanctuary in 1989.
It is considered part of the Western Forest Complex. Places adjacent to Umphang Wildlife Sanctuary are (from the north clockwise): Myanmar, Mokro and Phop Phra District in Tak Province, Khlong Wang Chao National Park, Khlong Lan National Park, Mae Wong National Park, and Thung Yai Naresuan Wildlife Sanctuary.
The highlight of this protected area is Thi Lo Su, the largest waterfall in Thailand and one of biggest waterfalls in Asia. Its name means "black waterfall" in Karen language. There are multiple falls, streams and pools to bathe in and whilst the most spectacular time to visit is between July and November, water flows throughout the year. It is located about 3 km (1 mi) from the wildlife sanctuary office.