Mairwa community development block (CD block) or Mairwa block is a notified area (community development block) in Siwan district in the Indian state of Bihar. It is one of 13 blocks of Siwan subdivision that touches Border with Uttar Pradesh .
The total area of the block is and the total population of the block is 113,499. Mairwa city is the headquarters of this block.
It also having significant cultural influence all around because of BABA HARIRAM TEMPLE in Mairwa Dham and it was there for last 418 years.
The block is divided into one nagar panchayat (urban) and many gram panchayats (rural).
Some villages of Mairwa block in different panchayats are:
Mairwa, situated in the western part of Bihar, borders the Indian state of Uttar Pradesh. It was originally a block of Siwan district, approximately 20 km from Siwan which in ancient days formed a part of Kosala Kingdom. It is geographically situated at 25ú35 North and 84ú1 to 84ú20 East. Mairwa is bounded on the east by the Siwan district headquarters, on the north by Gopalganj district and on the west and south by two districts of Uttar Pradesh: Deoria and Ballia.