Mairwa City Council is a Nagar Panchayat (City council) located in Siwan district of Bihar in India. The total area of the Council is 6.23 square kilometres (2.41 sq mi) and total population is 23,565. The city is divided into total 13 wards. It is the block headquarter of Mairwa block. It is famous for the historical temple Baba HariRam Brahma.