Buxar district is one of the 38 districts of Bihar, India. Located in the southwestern part of the state, it is a primarily agricultural district. The district headquarters is at the town of Buxar. Buxar district was carved out from Bhojpur district on 17 March 1991.

Buxar is a nagar parishad city in the state of Bihar, India, sharing border with Balia and Ghazipur district of Uttar Pradesh. It is the headquarters of the eponymous Buxar district, as well as the headquarters of the community development block of Buxar, which also contains the census town of Sarimpur along with 132 rural villages.