Bahadurpur is a legislative assembly constituency of Bihar, located in Darbhanga district of the state. The current MLA from this constituency is Madan Sahni of JD(U) who secured 68,538 votes in the 2020 legislative assembly elections. He defeated Ramesh Choudhary of Rashtriya Janata Dal (RJD) by a margin of 2,629 votes.

According to Election Commission data from 2024, 3,11,991 voters are eligible and have been registered in the constituency. 1,65,032 of these electors are male, 1,46,947 are female and 12 electors belong to the third gender. Past election data from 2020 showed the total number of registered electors at 3,00,009 where 1,59,496 registered electors were male, 1,40,500 electors were female and 13 electors were of the third gender. The 2015 election data shows that there were 2,68,823 registered voters in the constituency, where 1,44,371 electors were male, 1,24,448 electors were female and only 4 electors belonged to the third gender. 

In the 2020 elections, 1,78,188 out of the 3,00,009 total registered electors cast their votes, taking voter turnout to 59.39%. In the 2015 elections 1,56,431 out of the 2,68,823 electors participated in polling, keeping voter turnout at 58.19%. 

Polling for this constituency in this year's elections was held in the first phase of on November 6, 2025.

Bahadurpur constituency covers an approximate land area of 299.38 square kilometers and the geographic coordinates of Bahadurpur are 26° 06 '07.9"N 85° 57' 18.7"E. Seven other state assembly constituencies in the state of Bihar share borders with Bahadurpur constituency, which are Darbhanga, Keoti, Gaighat, Kalyanpur, Hayaghat, Benipur and Darbhanga Rural.