Jamui is a city and a municipality in Jamui district in the Indian state of Bihar. It is the district headquarters of Jamui district. Jamui was formed as a district on 21 February 1991 as a result of its separation from Munger.
Historical existence of Jamui has been observed from the Period of Mahabharta war. Archaeological and historical evidence shows its close association with Jain tradition for a long past to the present time.