Weixi Lisu Autonomous County is located in the northwestern part of Yunnan Province and the southwestern part of Diqing Tibetan Autonomous Prefecture. Its geographical coordinates range from 26°53′N to 28°02′N and from 98°54′E to 99°34′E. It is situated in the heart of the Three Parallel Rivers World Natural Heritage area, where the Jinsha River, Lancang River, and Nu River run parallel. To the east, it borders Shangri-La City; to the south, it adjoins Lanping Bai and Pumi Autonomous County of Nujiang Lisu Autonomous Prefecture; to the southeast, it connects with Yulong Naxi Autonomous County of Lijiang City; to the west, it borders Gongshan Derung and Nu Autonomous County and Fugong County of Nujiang Lisu Autonomous Prefecture; and to the northeast and north, it is adjacent to Deqin County. The county has a maximum east-west width of 70 kilometers and a maximum north-south length of 122 kilometers, with a total administrative area of 4,476.67 square kilometers.