Longleng is a district in the state of Nagaland, located in northeastern India. It is situated in the eastern part of Nagaland and is bordered by the districts of Tuensang and Mon to the north, Mokokchung to the west, and Tuensang and Myanmar to the east.

The district headquarters of Longleng is the town of Longleng. The area is predominantly inhabited by the Phom tribe who are known for their rich cultural heritage and traditional practices. The district is characterized by its picturesque landscapes, lush green hills and serene valleys.