Mon is located in the northeastern edge of Nagaland. It is bounded by the Indian states of Arunachal Pradesh to the north, Assam to the west, and shares a vital international border with Myanmar to the east. The town itself is situated on a steep ridge, characteristic of the Patkai mountain range foothills.
The physical geography is defined by its rugged, hilly terrain, deep valleys, and dense subtropical broadleaf forests. Rivers such as the Tizit and Tapi cut through the valleys, providing vital water sources and drainage into the Brahmaputra basin in Assam. Deforestation due to traditional shifting cultivation has altered some of the primary forest cover, but the region remains vividly green.
