Ramnagar (Vidhan Sabha constituency) (Hindi: रामनगर विधान सभा निर्वाचन क्षेत्र) is an assembly constituency in Paschim Champaran district in the Indian state of Bihar. It is reserved for scheduled castes. It was earlier an open seat.
As per orders of Delimitation of Parliamentary and Assembly constituencies Order, 2008, 2. Ramnagar (Vidhan Sabha constituency) (SC) is composed of the following: Ramnagar and Gaunaha community development blocks.
Ramnagar (Vidhan Sabha constituency) is part of 1. Valmiki Nagar (Lok Sabha constituency). It was earlier part of Bagaha (Lok Sabha constituency).
Election results 
In the November 2010 state assembly elections, Bhagirathi Devi of BJP won the 2 Ramnagar assembly seat defeating her nearest rival Naresh Ram of Congress. Contests in most years were multi cornered but only winners and runners are being mentioned. Chandra Mohan Rai of BJP defeated Fakhruddin Khan representing RJD in October 2005 and representing LJP in February 2005, and Mohammad Salauddin of NCP in 2000. Ram Prasad Yadav of JD defeated Chandra Mohan Rai of BJP in 1995. Chandra Mohan Rai of BJP defeated Sheikh Sarfuddin of JD in 1990. Arjun Vikram Shah of Congress defeated Chandra Mohan Prasad Rao representing BJP in 1985, Hari Shankar Tiwari of BJP in 1980 and Chandra Mohan Prasad Rao representing Janata Party in 1977.