Mohanpur lies in the southern tip of Jamui District , near Bihar’s border with Jharkhand. The place is situated at an altitude of 849 ft above sea level and is 59 km south of Jamui.
Patna Airport is the nearest airport. The rail route linking Simultalla with Jasidih passes through the town. Simultalla Railway Station, 11 km to the north, is the closest major railhead.