Hasanpur is an assembly constituency in Rosera Subdivision of Samastipur district in the Indian state of Bihar.
Hasanpur Assembly constituency is composed of the following: Hasanpur and Bithan community development blocks; Kundal I, Kundal II, Shalepur, Jahangirpur and Bishnupur Diha gram panchayats of Singhia CD Block.
Hasanpur Assembly constituency is part of No. 25 Khagaria (Lok Sabha constituency).
Hasanpur Road Junction Railway Station is the busiest station in Samastipur-Khagaria Line.