Barharia is a Community development block and a town in the northern part of the Siwan District in the Indian state of Bihar. It is one out of 13 blocks located in Siwan Subdivision. Barharia is surrounded by to the North, Siwan Block to the South, to the East, and towards North. Mirganj, Siwan, Barauli, and Gopalganj are nearby cities. The total population of Barharia is 321,292 as of 2011 census and the total area of block is 177.27 square kilometres (68.44 sq mi). Barharia town is the headquarter of this block.