What is now known as Bauchi was until 1976 a province in the then North-Eastern State of Nigeria. According to the 2006 census, the state has a population of 4,653,066.

Bauchi State has gone through tremendous transformation over the years. The Ajawa language was spoken in Bauchi State, but became extinct between 1920 and 1940 as speakers switched to Hausa.

During the colonial era up to independence, it formed part of the Bauchi Plateau of the then Northern Region, until the 1967 state creation exercise, when the Bauchi, Borno, and Adamawa provinces constituted the former North-Eastern State.

With the creation of Bauchi State in 1976, then comprising present Bauchi and Gombe States, it included 16 local government areas. The number of local government areas in the then Bauchi State was increased to 20 and later to 23. However, in 1997 when Gombe State was created out of Bauchi and additional local governments were created in the country, Bauchi State was left with 20 local government areas as shown below.

Sharia law was adopted in June 2001.