History of Deoria District states that the current area of this district was a part of `Koshal rajya`- a prime centre of ancient `Arya culture`. Besides many fictions related with this area, astro-historical fossils found at many places of this district, show that there was a developed and organised society long ago. Ancient history of the district is related with Ramayana era when Lord Rama appointed his elder son `Kush` as the king of Kushawati, which is presently known as Kushinagar.

Early history of Deoria District also states that before Mahabharata era, this area was associated with Chakravorty Samrat `Mahasudtsan`. His kingdom `Kushinagar` was well developed and was prosperous. Nearby was a vast forest area, which was known as `Maha-van`. This area was under control of Maurya rulers, Gupta rulers and Bhar rulers, and then it came under the control of Garhwal ruler `Govind Chandra` from 1114 to 1154. Medieval history of Deoria District is not very clear. It says that this area was probably under the control of Awadh rulers or under the Muslim rulers of Bihar. There was little control of oldest Delhi rulers, Sultan, Nizam or Khilji on this region. Further, there is no description of this area in the medieval period during Muslim invasion.

Many places of Deoria District played an important role in the modern history associated with this region. Important ones are; Baikunthpur, Gaura Barhaj, Rudrapur, Hata, Kasia, Gauri Bazar, Kaptanganj, Udhopur, Tamkuhi, Basantpur Dhoosi, etc. Mahatma Gandhi addressed Deoria and Padrauna public meetings in 1920. In 1931, wide movements against government and landlords started in the district. Many more people joined Congress as volunteers and marched several places of the district. During the Quit India Movement, Deoria District played an active role.

As per the history of Deoria District, it came into existence on 16th of March, 1946. This district was carved out from Gorakhpur District. The name Deoria is derived from `Devaranya` or probably `Devpuria` as believed. According to official gazettes, the name of the district was taken from district headquarters `Deoria` and the term Deoria generally means a place where there are temples. Deoria name developed from the remnants of an ancient Shiva Temple of the region. Kushinagar District came into existence in 1994 by separating north-east portion of Deoria District.