Buxar district is one of the thirty-eight districts of Bihar state, India. The district headquarters are located at Buxar. Before 1992, it was part of Bhojpur District, Bihar. The major towns are Dumraon, Itarhi and Rajpur.

Buxar district occupies an area of 1,703 square kilometres (658 sq mi), comparatively equivalent to Australia’s Bathurst Island.

The town Buxar is located on the bank of river Ganges (Ganga). A road bridge (Veer Kunwar Singh Setu) over Ganges connects Buxar with Ballia District of neighboring state Uttar Pradesh. The town is connected to the state capital Patna by rail and road routes. Substantial proportion of trade activities are with well connected towns and cities in Uttar Pradesh such as Varanasi, Ballia, Ghazipur, Lucknow. There are direct trains from Buxar to the metro cities of india like Banglore, Delhi, Jaipur, Kolkata, Ahmedabad, Mumbai etc.

According to the 2011 census Buxar district has a population of 1,707,643, roughly equal to the nation of The Gambia or the US state of Nebraska.This gives it a ranking of 285th in India (out of a total of 640).The district has a population density of 1,003 inhabitants per square kilometre (2,600/sq mi).[4] Its population growth rate over the decade 2001–2011 was 21.77%.Buxar has a sex ratio of 922females for every 1000 males, and a literacy rate of 71.77%.