Siddharthnagar district, a part of Basti division is a district of Uttar Pradesh state with its administrative headquarters located at Navgarh town. The district got its name from the pre-enlightenment name of Lord Buddha i.e. Siddhartha. Earlier, the district was a part of Kapilavastu and he was in Kapilavastu till the age of 29 years. According to some people the present day’s Piprahwa, located at a distance of 22 kms. from Naugarh is the ancient Kapilavastu. Since, Shakya clan made Kapilavastu as their capital and the ruler of this clan was the father of Gautam Buddha hence Lord Buddha is also well known as Shakyamuni. The place of Siddharthnagar is very blessed since it has produced numerous freedom fighter namely Qazi Adeel Abbasi (Bayara Qazi), Haji Noorul Haque (Naugarh Bazar) and Maulana Abdul Qayyum Rahmani (Mufassar-e-Quran). Prabhu Dayal Vidyarthi Van Ganga Bridge on the Farenda Naugarh-Barhni Shravasti Road in the district is named after the prominent freedom fighter, Prabhudayal Vidyarthi in order to honour him. The current Siddharthnagar district was emerged as a separate district on 29th December, 1988 after the division of the Basti district. The new district included the Northern portion of the former Basti district. The present day’s Siddharthnagar district consists of several villages mainly Piprahwa and Ganvaria.

Prabhudayal Vidyarthi, a distinguished freedom fighter, Gandhian, writer, social worker and politician was born in 1925 at Jogiya Udaipur in the Siddarthnagar district. In order to honour his memory the Government of Uttar Pradesh named the bridge on Farenda Naugarh-Barhni Shravasti Road in Siddharth Nagar as "Prabhu Dayal Vidyarthi Van Ganga Bridge".

Geographically, the district lies at 27°26'N latitude, 83°01'E longitude and 370 m altitude. In the year 2021, there was a total 1.50% forest area of total geographical area. The district encompasses a geographical area of 2,895 sq kms. and in terms of geographical area it occupies the ranks of 44th in the state and 403rd in India. It is bounded by Nepal on the north, Basti district and Sant Kabir Nagar district on the south, Maharajganj district on the east and Gonda district and Balrampur district on the west. The prominent rivers that flows through the district are Rapti. The climate of the district remains extremely hot during the summer. Most of its rainfall occurs in the monsoon season. The actual rainfall in the district was 1624.5 mm in the year of 2021-22.

Administration wise, the district is divided into 5 tehsils namely Naugarh, Shohratgarh, Bansi, Itwa (Siddharth Nagar) and Domariyaganj. There are 1 Lok Sabha seat and 5 Assembly constituencies in the district. Moreover, the district comprises 5 sub-districts, 8 towns and 2,505 villages. The administrative language in the district is Hindi.

According to 2011 census the district has a population of 25,59,297 out of which 12,95,095 are males and 12,64,202 are females. The district has a sex ratio of 976 females for every 1000 males. During the year 2001-2011 the population growth rate in the district was 25.45% including 23.68% were males and 27.32% were females. The population density the district is 884 persons per sq. kms. In the year 2020 the number of live births in the district was 60,555 including 31,351 were males and 29,204 were females. In the same year the number of deaths in the district was 14,434 out of which 7,438 were males and 6,996 were females. As per 2011 census the major religion in the district is Hindu with 69.93% of the total population. According to 2011 census the principal languages in the district is Hindi with 95.22%.

The economy of the district is solely dependent on agriculture. Most of the lands of the district are used for agricultural purposes. Some of its chief agricultural products are paddy, wheat, maize, different types of pulses, oil seeds, potato, sugarcane, etc. The adoption of the new agricultural technologies amongst the farmers of the district helps to increase the production of various agricultural items. More than half of the population in the district are engaged in agriculture since it is scantily industrialised. In 2006 the Ministry of Panchayati Raj declared Siddharthnagar as one of the country's 250 most backward districts that is currently receiving funds from the Backward Regions Grant Fund Programme (BRGF). In the year 2020-21 the gross domestic product in the district was Rs. 13,39,693 lakh at Current Price and Rs. 8,01,920 lakh at Constant Prices during the year 2011-2012. The Net Domestic Product in the district during the period 2020-21 was Rs. 11,90,740 lakh at Current Price and Rs. 6,90,756 lakh at Constant Prices in the year 2011-2012. The Per Capita Income or NDDP, At Factor Cost in the district during the period 2020-21 was Rs. 38,715 at Current Price and Rs. 22,459 at Constant Prices in the year 2011-2012.

The district is an abode of numerous reputed educational institutions. It provides platform for higher education. Some of its recognised educational institutions are Ratan Sen Degree College, Ratan Sen Inter College, Tilak Inter College, Government Girls Inter College, etc. As per 2011 census the literacy rate in the district is 59.25% including 70.92% are males and 47.41% are females.

Rampal Singh, an eminent Indian politician and a member of 10th, 12th and 13th Lok Sabha from Domariyaganj constituency was born on 1st September 1930 Sikta village in the Siddarthnagar district. He is a member of Bhartiya Janata Party.

During the year 2021, there were 3,70,975 domestic tourists and 90 foreign tourists who visited these places of the district. The district has numerous centres of attraction with historical and religious significance which allures travellers from different parts of the country as well as world. Yogmaya Temple, one of the most pious places in the district is located at the Jogiya village. Natives of the district believe that earlier this temple was popularly called as Mahamaya temple, named after the mother of Siddhartha or Gautama Buddha. Pilgrims from far distance place come to this temple to offer their prayers. Some other places of interest in the district are Piprahava, Bharat Bhari, Paltadevi Temple, Banganga Barage, etc.