Kailasahar is situated in northern Tripura, sharing a porous and heavily guarded international border with the Sylhet division of Bangladesh to the north and northwest. The town is primarily built along the fertile floodplains of the Manu River, one of the major rivers of Tripura, which originates in the hill ranges and flows northward into Bangladesh.
The physical geography is defined by a lush, green landscape characterized by dense tropical vegetation, agricultural fields, and sprawling tea gardens. The region is rich in natural beauty, with small rivulets and streams crisscrossing the area before joining the Manu River. The surrounding region is predominantly agrarian, benefiting from the nutrient-rich alluvial soil deposited by river flooding.