The Gandhawaria (also known as Gandhawariya or Gandhwaria) are a Rajput clan based in the Mithila region of northern Bihar and some adjoining districts of the Terai. They are a sub-clan of the Parmar Rajputs. They acquired power after the fall of the Oinwar dynasty in the 14th century and ruled estates throughout the region.
Most of the estates they ruled were in Tirhoot, Saharsa, Sonbarsa Raj and Madhepura.
The Gandhawariya trace their descent from Prithi Raj Singh, who migrated from Malwa and settled in the village of Gandhwari in Madhubani district. His descendant Lakhesh Singh annexed extensive territories in Mithila/Tirhut. One of the descendants Raja Keshri Singh obtained the title of Raja from the Emperor of Delhi. It is said that the Raja of Darbhanga Raj refused to recognize the Rajship conferred upon Raja Keshri Singh and hence a battle took place between the armies of Raja Keshri Singh and the Raja of Darbhanga in which the armies of both sides suffered casualties. Both parties eventually came to terms and Tiljuga River was fixed as the boundary of their dominions.
Some have also connected the Gandhawaria to the Karnata dynasty of Mithila since the ruins of Bheet Bhagwanpur are similar to the Karnata tradition of blackstone and bear a marked resemblance to them. Many Gandhawaria's can also trace their descent to the Karnata King, Malladeva.