Lower Subansiri is a district located in the state of Arunachal Pradesh in northeastern India. It is one of the 25 districts in the state and is situated in the Subansiri River Valley. The district shares its borders with several other districts of Arunachal Pradesh, namely Upper Subansiri, Papum Pare, Kurung Kumey, and Kamle.

The district headquarters of Lower Subansiri is Ziro, which is a scenic town known for its picturesque landscapes and rich cultural heritage. Ziro is inhabited by the Apatani tribe, who are known for their unique agricultural practices and traditional customs.