Sadulpur ,(previously known as Rajgarh) is a city, municipality, tehsil and Legislative Assembly seat in Churu district of northern part of Rajasthan state in India. It was the territory of the gaur dynasty later after defeated in war with shekhawat rajputs ,It lies in Shekhawati region at an elevation of 239 m (784 ft). To distinguish Rajgarh from several other places with same name, Sadulpur has become a synonym of Rajgarh town's name in recent times.

Rajgarh is named after Maharaja Raj Singh I of Bikaner. It was part of Shekhawati where Shekhawat branch of Rajputs had ruled. Great Raj Fort was built in 18th century by Maharaja Raj Singh I of Bikaner. Most Muslims in the town had migrated here from Narhar during the construction of the fort.

The area of Rajgarh was granted by HH Maharao Shri Sir Madho Singh Ji Bahadur in 1930 to his son. Maharajkumars were:

• Maharajkumar Bijay Singh (1930-1956)
• Maharajkumar Ajaypratap Singh (1956-1967)
• Maharajkumar Baghwatpratap Singh (1967-2000)
• Shri Sahib Anshupratap Singh (2000–present)
• Sahib Jagannath Singh

Rajgarh is a municipality and city in Churu district of Rajasthan. The Rajgarh city is divided into 40 wards for which elections are held every 5 years. In 2011, Rajgarh Municipality had administration over total 9,902 houses to which it supplies basic amenities like water and sewerage. It is also authorize to build roads within Municipality limits and impose taxes on properties coming under its jurisdiction.

In 2011, Rajgarh Municipality had a population of 59,193 of which 30,710 are males while 28,483 are females as per report released by Census of India 2011. Population of Children with age of 0-6 is 8122 which is 13.72% of total population of Rajgarh (M). In Rajgarh Municipality, Sex Ratio is of 927 against state average of 928. Moreover Child Sex Ratio in Rajgarh is around 880 compared to Rajasthan state average of 888. Literacy rate of Rajgarh city is 72.72% higher than state average of 66.11%. In Rajgarh, Male literacy is around 83.30% while female literacy rate is 61.41%. Out of the total population, 19,699 were engaged in work or business activity. Of this 15,286 were males while 4,413 were females. In a census survey, the worker is defined as a person who does business, job, service, and cultivator and labor activity. Of the total 19699 working population, 88.96% were engaged in main work while 11.04% of total workers were engaged in marginal work. A large number of skilled and unskilled laborers from Sadulpur are working abroad in places such as Dubai, Oman, Qatar, Kuwait, and Saudi Arabia.

Rajgarh is located at28°22′N 75°14′E / 28.36°N 75.24°E / 28.36; 75.24. The area is located on bagar tract which runs along Haryana-Rajasthan border.

The region has record temperatures ranging from below freezing point in the winter to over 50 °C in summer. The District of Churu is also the hottest zone in the country.

The town has a wholesale market for commodity trading. Trading of commodity products is always a hot business for the locals in the small town. Sadulpur is also famous for delicious Sweets, Common Sweets available here are Sitta, Peda, Kaju katli, Kalakand (Milk cake made from milk / Mawa/Khoa).

The town has a post-graduate college (Mohta PG College) affiliated to University of Bikaner, Balika Mahavidalya, and Government College, also affiliated to Maharaja Ganga Singh University, Bikaner. There are several higher secondary, secondary, and primary schools in Rajgarh, some of them are Mohta public School, Chandgiram Public School, Senior High Secondary, Lords International school.

Rajgarh is connected to Bikaner, Jaipur, Delhi and other cities by road. It is about 240 km from Delhi by NH-10 via Rohtak, Hisar (170 km), then needs to take NH-52 on Kaithal-Hisar-Jodhpur Road (70 km). Shorter route from Delhi is via Rohtak, Bhiwani, Bahal (around 210 km). The National Highway No-52 passing through Rajgarh via Dokwa, Dudhwa Khara, Churu, Fatehpur, Salasar, etc. The State Highway No-41 passing through Rajgarh via Lambore, Jhunjhunu, etc. Malsisar. A bypass road attaches to NH52 to Taranagar, Bhadra, Hisar road. The National Highway No-709 Ext. also ending at Rajgarh.

Sadulpur Junction railway station, named after Maharaja Sadul Singh of Bikaner, is the name of main railway station in Rajgarh, which is the largest railway station in Churu district.It lies on Delhi-Rewari-Loharu-Sadulpur-Churu-Bikaner rail, Hisar-Sadulpur-Churu-Jodhpur rail and Sriganganagar-Jaipur rail links. Routes have been electrified and Sadulpur rail bypass cabin was constructed to enable goods train to bypass Sadulpur. After 2011, the metre gauge track was converted to 5 ft 6 in (1,676 mm) broad gauge.

Several trains now connect Rajgarh and Sadulpur to major cities Delhi, Bikaner, Jaipur, Lucknow, Degana, Sri Ganganagar, Hisar, Hanumangarh, Mumbai, Kolkata, Ahmedabad, Howrah, Jammu Tawi, ludhiana, Guwahati, and Pathankot.

Bus transportation facility can be availed to Hisar, Kaithal, Jaipur, Pilani, Churu, Rohtak.

The nearest airports are New Delhi Airport, Jaipur Airport and Hisar Airport, Bikaner Airport,is a domestic airfort.

• Bimal Jalan, a former Governor of India's Reserve Bank and Rajya Sabha member
• Devendra Jhajharia, Paralympic javelin thrower, only Indian to win two gold medals at Paralympics.
• Krishna Poonia, Padam Shri awardee, Olympian and MLA
• Lakshmi Mittal, steel tycoon born in tehsil Sadulpur (Rajgarh) of Churu district
• Sajjan Singh Malik was in Indian Army Special Force who got posthumous Kirti Chakra for his acts of bravery in fighting with terrorists on 7 July 2004 in Gundpura village of Baramula district. He killed three terrorists before becoming martyr.

• List of districts of Rajasthan