|• Total||2,752 km2 (1,063 sq mi)|
|• Density||882/km2 (2,280/sq mi)|
|• Official||Hindi, Urdu|
|Time zone||IST (UTC+5:30)|
|Vehicle registration||UP 55|
|Literacy||67.81 per cent%|
|Lok Sabha constituency||Domariyaganj|
|Vidhan Sabha constituency||5|
Siddharthnagar district (Hindi: सिद्धार्थनगर ज़िला, Urdu: سدھارتھ نگر ضلع) is one of the 75 districts of Uttar Pradesh state in Northern India. Naugarh town is the district headquarters. Siddharth Nagar district is a part of Basti division. The district is known for the ruins of the Shakya Janapada, at Piprahwa. 22 km from the district headquarters Naugarh. According to Government of India, the district Siddharthnagar is one of the minority concentrated districts in India on the basis of the 2001 census data on population, socio-economic indicators and basic amenities indicators.
The district was named after prince Siddhartha, the pre-enlightenment name of Buddha, as he spent his early years (till the age of 29 years) in Kapilavastu, parts of which included territory in this district.
Siddharthnagar district was carved out on 29 December 1988 by bifurcating Basti district. The new district comprised the Northern part of the erstwhile Basti district.
Today's Piprahwa (22 km from Naugarh) is identified by some people with ancient Kapilavastu where Buddha spent the early years of his life. Kapilavastu was the capital of the Shakya clan whose ruler was the father of Gautama Buddha, and therefore Lord Buddha is also called as Shakyamuni. The Shakya domain was one of the sixteen independent principalities of the 6th century BC.
Prince Siddhartha, as the Buddha was then known, left his palace in Kapilvastu at the age of 29, and revisited 12 years later, after attaining enlightenment.
Today, Siddharthnagar district comprises several villages, mainly Piprahwa and Ganvaria. A large stupa stands at the ancient site which is said to have housed the bone relics of Lord Buddha. The presence of these relics is testified by an ancient Brahmi inscription found at Piprahwa. The ruins of the royal palace are spread over a large area. Excavations by archaeological survey of India have revealed the relation of this place to the Kushan period. An excavated stupa bears text that proves the existence of an ancient monastery named Devaputra in this place. Two mounds have also been excavated at only a little distance (1.5 km) from this village which, is considered to be the ruins of King Suddhodhana's palace.
Notable individuals of the region Ahmad Hussain Akrahra, Khajuria Baadshah Mehdi Hasan Khan Khajuria, freedom fighter Qazi Adeel abbasi, Qazi Iftekhar Ahmad, Late Haji Noorul Haque (Naugarh Bazar) and Maulana Abdul Qayyum Rahmani. Saddened by communal riots and massacre during partition of India, Maulana Abdul Qayyum Rahmani, an eminent leader of Congress, abandoned politics and settled down in his native place village of Dudwania to spent his remaining life. Freedom Fighter Prabhudayal Vidyarthi, arrested at Sevagram and put in isolation cell from 1942 to 1945, in Nagpur Jail, Maharashtra, belonged here. The bridge on Farenda Naugarh-Barhni Shravasti Road is named Prabhu Dayal Vidyarthi Van Ganga Bridge to honour him.
Siddharthnagar district lies between 27°N to 27°28'N and 82°45'E to 83°10'E. It is part of Purvanchal. The district borders Nepal's Kapilvastu district on the north and Rupandehi district on the northeast. Otherwise it is surrounded by other districts of Uttar Pradesh: Maharajganj on the east, Basti and Sant Kabir Nagar on the south, and Balrampur on the west. Siddarthnagar's area is 2,752 km2.
In 2006 the Ministry of Panchayati Raj named Siddharthnagar one of the country's 250 most backward districts (out of a total of 640). It is one of the 34 districts in Uttar Pradesh currently receiving funds from the Backward Regions Grant Fund Programme (BRGF).
Siddharthnagar district comprises 5 tehsils;
5 Vidhan Sabha constituencies are located within this district. These are Shohratgarh, Kapilvastu, Bansi, Itwa and Domariyaganj. The only Lok Sabha constituency in this district is the Domariyaganj.
There are many places to visit within the district.
- Yogmaya Temple a divine place, located in the village Jogiya, where people come to make a wish every monday and friday by offering devi a kadahi and prasad of puri and sweet halva. Mundan for young children is also performed in the vicinity of the temple. Every year a big two day mela is held here on Dev Diwali or Kartik Purnima, when people bathe in the nearby river and make a wish to maa yogmaya. People find peace of mind in this divine place. It is also believed that this temple was called Mahamaya temple, named after the mother of Siddhartha or Gautama Buddha 
- Banganga Barage
According to the 2011 census Siddharthnagar district has a population of 2,553,526,  roughly equal to the nation of Kuwait or the US state of Nevada. This gives it a ranking of 164th in India (out of a total of 640). The district has a population density of 882 inhabitants per square kilometre (2,280/sq mi) . Its population growth rate over the decade 2001-2011 was 25.17%. Siddharth Nagar has a sex ratio of 970 females for every 1000 males, and a literacy rate of 67.81%.
Minority population is about 27% of the total population of the district. Siddharth Nagar is a category "A" district, that is having socio-economic and basic amenities parameters below the national average.
This district has produced many political personalities and national icons. Freedom Fighter and prominent leader Prabhudayal Vidyarthi, who lived with Gandhi at Sevagram Wardha, belonged to Jogiya Udaipur of Siddartha Nagar. Freedom fighter and former state minister Kazi Jalil Abbasi belongs to Bayara Village of Siddhartha Nagar. Freedom fighter and ex-MLA Mathura Prasad Pandey was a prominent politician of this region, Lt. Minister Dinesh Singh was the one who played important role in making the government of Samajwadi Party in 2003. Currently Shri Mata Prasad Pandey is the prominent political face from Siddharthanagar District. He is currently Speaker of Uttar Pradesh Legislative Assembly. Jagdambika Pal(who was among the most renowned person in Indian National Congress and has recently joined the Bharatiya Janata Party) also contests in election from Dumariyaganj(Parliamentary seat in Siddharthanagar District. Ex-MLA Mrs Kamla Sahni w/o Prabhudayal Vidyarthi (who got Siddharthnagar bifurcated from Basti and 40km lakhnapar-baidaullah dam in kachchar/terai area) belongs here. Ex- minister Abhimanyu Prasad Pandey, Taufeeq Ahmad, Mohammed Muqeem and Kamal Yusuf Malik (ex. state minister in State Government),Swayamber Chaudhary (ex-MLA BJP), Maulana Hamidullah Chaudhary (President NCP Siddharth Nagar),Ram Kripal Chaudhary (son of Swayamber Chaudhary and ex-zila panchayat member) also belong to this district. The great socialist leader, Samajwadi Party's 5 times MP and Vice President of Samajwadi Party Late Sri.Brij Bhushan Tiwari was the prominent and biggest face in politics who also belongs to Jamuni, a small village of Soharathgarh tehsil of this district. A rising socialist shri.Avdhesh kumar yadav son of late shri Lalta prasad (teacher) who belongs to imiliya sumali,a small village of barhni block of this district who also contested in jila panchayat sadasya election in 2010. At present young scientist turned social activist Er QAZI Imran Lateef'' is well known face of Aam Aadmi Party in Uttar Pradesh belongs Siddharthnagar district . Er Imran is consistently working hard for betterment of district Siddharthnagar under the banner of Aam Aadmi Party. Recently in Delhi Assembly Elections, he was very popular among Muslim voters for his inspirational public speeches.
- [PDF]LegalSoft - Online Legal Library - India Law Legal Database legaldatabase.in/LegalDB/Home/ExportToPdf?SID=f1c803f3-d4f7... 24 May 2002 - known as 'Prabhu Dayal Vidyarthi Van Ganga Bridge', Siddharth Nagar. ...
- Ministry of Panchayati Raj (8 September 2009). "A Note on the Backward Regions Grant Fund Programme" (PDF). National Institute of Rural Development. Retrieved 27 September 2011.
- "District Census 2011". Census2011.co.in. 2011. Retrieved 2011-09-30.
- US Directorate of Intelligence. "Country Comparison:Population". Retrieved 2011-10-01.
- "2010 Resident Population Data". U. S. Census Bureau. Retrieved 2011-09-30.
- MINUTES OF THE 34th MEETING OF EMPOWERED COMMITTEE TO CONSIDER AND APPROVE REVISED PLAN FOR BALANCE FUND FOR THE DISTRICTS OF GHAZIABAD, BAREILLY, BARABANKI, SIDDHARTH NAGAR, SHAHJANPUR, MORADABAD, MUZAFFAR NAGAR, BAHRAICH AND LUCKNOW (UTTAR PRADESH) UNDER MULTI-SECTORAL DEVELOPMENT PROGRAMME IN MINORITY CONCENTRATION DISTRICTS HELD ON 22nd JULY, 2010 AT 11.00 A.M. UNDER THE CHAIRMANSHIP OF SECRETARY, MINISTRY OF MINORITY AFFAIRS. F. No. 3/64/2010-PP-I, GOVERNMENT OF INDIA, MINISTRY OF MINORITY AFFAIRS
||Western Development Region, Nepal|
|Balrampur district||Maharajganj district|
|Gonda district||Basti district||Gorakhpur district
Sant Kabir Nagar district