Raja Pakar (Vidhan Sabha constituency) (Hindi: राजापाकर विधान सभा निर्वाचन क्षेत्र) is an assembly constituency in Vaishali district in the Indian state of Bihar. It is reserved for scheduled castes.
As per Delimitation of Parliamentary and Assembly constituencies Order, 2008, No. 127 Raja Pakar (Vidhan Sabha constituency) is composed of the following: Raja Pakar, Desri and Sahdei Buzurg community development blocks.
Raja Pakar (Vidhan Sabha constituency) (SC) is part of No. 21 Hajipur (Lok Sabha constituency) (SC).
In the 2010 state assembly elections, Sanjay Kumar of JD(U) won the newly created Raja Pakar assembly seat defeating his nearest rival Gaurishankar Paswan of LJP.