Chhatapur Assembly constituency is an assembly constituency in Supaul district in the Indian state of Bihar. It has been an open seat since 2010, but earlier it was reserved for Scheduled Castes. There are a total of 23 gram panchayat under the Chhatapur block.
As per Delimitation of Parliamentary and Assembly constituencies Order, 2008, No. 45 Chhatapur Assembly constituency is composed of the following: Chhatapur and Basantpur community development blocks.
Chhatapur Assembly constituency is part of No. 8 Supaul (Lok Sabha constituency).