Umphang is the southernmost district (amphoe) of Tak Province, Thailand, established by the Royal Decree Establishing Amphoe Umphang, BE 2502 (1959), which came into force as from May 6, 1959.
The district is at the Thai-Burmese border. It is also the name of the town center of the district. Neighboring districts are (North from clockwise): Amphoe Phop Phra; Amphoe Khlong Lan and Amphoe Pang Sila Thong of Kamphaeng Phet Province; Amphoe Mae Wong and King Amphoe Mae Poen of Nakhon Sawan Province; Amphoe Ban Rai of Uthai Thani Province; and Amphoe Thong Pha Phum and Amphoe Sangkhla Buri of Kanchanaburi Province. The western edge of the district has a long boundary with Burma. Surrounded by national parks and wildlife reserves, it is one of the least accessible district in Thailand. Nevertheless, it has one major tourist attraction, Thi Lo Su Waterfall, the largest waterfall of Thailand