Jehanabad (also spelled Jahanabad) is a district of Bihar state in India. It derives its name from its headquarters town of the same name. The district is situated in between 25-0’ to 25-15’ degree North latitude and 84-31’ to 85-15’ East Longitude. Its surrounding districts are the district of Patna in north, Gaya in south, Nalanda in east and the newly created district of Arwal in the west.

Area of this district is 1,569 sq km with a population of 1,125,313 as per census 2011.

Sub Divisions - Jehanabad.
Blocks - Ghosi, Jehanabad, Makhdumpur, Kako, Sonebhadra, Bansi, Surjpur, Ratnifridpur, Hulasganj, Modanganj.
Agriculture - Paddy, Wheat, Lentils.
Rivers - Phalgu.

Jehanabad was carved out of old Gaya district on 1st August, 1986. It was a sub-division of Gaya since 1872.

Vidhan Sabha (Legislative Assembly) constituencies and their areas after delimitation order of 2008

216 Jehanabad Vidhan Sabha Constituency - CD Blocks Ratni Faridpur and Jehanabad.

217 Ghosi Vidhan Sabha Constituency in Bihar - CD Blocks Modanganj, Hulasganj & Ghoshi; Gram Panchayats Damuha, Purvi Kako, Pashchimi Kako, Khalispur, Bara, Utarserthua, Saidabad Parsain and Barawan of Kako CD Block.

218 Makhdumpur Vidhan Sabha Constituency (SC) - CD Block Makhdumpur; Gram Panchayats Sulemanpur, Pinjaura, Nerthua, Badhauna, Amthua, Dedhsaiya, Maniyawan and Nonhi of Kako CD Block.