Nganzai is a Local Government Area of Borno State in northeastern Nigeria. Its headquarters are in the town of Gajiram.

It has an area of 2,467 km2 and a population of 99,799 at the 2006 census.

The postal code of the area is 612.

It is one of the sixteen LGAs that constitute the Borno Emirate, a traditional state located in Borno State.

Jihadist groups carried out massacres in July 2019 and June 2020.