Loei is one of the most sparsely populated provinces (changwat) of Thailand, located in the North-East. Neighboring provinces are (from east clockwise) Nong Khai, Udon Thani, Nongbua Lamphu, Khon Kaen, Phetchabun, Phitsanulok. In the north it borders Xaignabouli and Vientiane Province of Laos.
The city of Loei is surrounded by mountain ranges whose summits are covered by fog and are abundant with various kinds of flora. The best known mountains in the province are Phu Kradueng, Phu Luang and Phu Ruea