| Banmankhi Bazar | |
| Settlement Type: | Town |
| Pushpin Map: | India Bihar |
| Pushpin Map Caption: | Location in Bihar, India |
| Coordinates: | 25.8833°N 87.1833°W |
| Subdivision Type: | Country |
| Subdivision Name: |  India |
| Subdivision Type1: | State |
| Subdivision Name1: | Bihar |
| Subdivision Type2: | Region |
| Subdivision Name2: | Mithila |
| Subdivision Type3: | District |
| Subdivision Name3: | Purnia |
| Unit Pref: | Metric |
| Population Total: | 25183 |
| Population As Of: | 2001 |
| Population Density Km2: | auto |
| Demographics Type1: | Languages |
| Demographics1 Title1: | Official |
| Demographics1 Info1: | Maithili, Hindi |
| Timezone1: | IST |
| Utc Offset1: | +5:30 |
| Blank1 Name Sec1: | Lok Sabha constituency |
| Blank1 Info Sec1: | Purnia |
| Blank2 Name Sec1: | Vidhan Sabha constituency |
| Blank2 Info Sec1: | Banmankhi |
Banmankhi Bazar is a town and a notified area in Purnia district in the state of Bihar, India.
Banmankhi is situated 32 km away from Purnea, the district town.
Banmankhi is a Sub-division.
India census,[1] Banmankhi Bazar had a population of 25,183. Males constitute 55% of the population and females 45%. Banmankhi Bazar has an average literacy rate of 52%, lower than the national average of 59.5%; with 64% of the males and 36% of females literate. 18% of the population is under 6 years of age.
Banmankhi Bazar is well known for a sugar manufacturing facility, but it is currently not functioning and is closed. The facility provided employment to many persons.
Private:Jeevan Jyoti resi. High schoolSaraswati Shishu MandirSant Paul's Mission School for primary and middle schooling,Tender Heart Public School. Public: Sumrit High school: 6-10+2(co-ed) MatuRam Kanya Uccha Vidyalaya: 6-10 (female), G. L. M. College: Higher Education (co-ed),J.C. Science College
Banmankhi is connected with Purnia, Madhepura, Saharsa and Dhamdaha (Subdivision of Purnia District) through highway. The town is served by .
Banmankhi Junction is a railway station of Banmankhi. It lies between Barauni-Katihar, Saharsa and Purnia sections of East Central Railway. This station is connected to,, Saharsa, Patna,,,, and .