Thoeng is a mountainous district. The conspicuous 1,174 m high Doi Ian rises 12 km to the east and 823 m high Doi Kham rises four km south of the town between Thoeng and Chiang Kham. There are some higher mountains in the east of the district such as 1,013 m high Doi Pha Mon and 1,442 m high Phu Chi Fa at the border with Wiang Kaen District. The Ing River, with its source in the Phi Pan Nam Range (Doi Luang in Mae Chai District, Phayao Province) flows through the plain area of Thoeng. Other rivers in the area are the Lao River, a tributary of the Kok River, from Doi Phu Lang Ka, Chiang Kham District, in the north and Ngao River from Doi Pha Mon and the Plong River.