Narnaul is a city, a Municipal Council, and location of headquarters of the Mahendragarh district in the Indian state of Haryana. It is located in the National Capital Region of India.

During the early Vedic period of Rigveda, this area was called the Nandigram where rishi Chyavana lived in his ashram. During the later Vedic period of Mahabharta, this area was called the Nara Rashtra which later became corrupted to Narnaul.

During the Mahabharta period, the Nara Rashtra, on the Hastinapur to Chambal route, was conquered by the youngest Pandava brother Sahdev.

Narnaul is built on a prominent tell, but the tell has never been excavated so the site's earliest history is unknown. The Muslim invader Shah Wilayat came to Narnaul in 1137 CE with sword and jewels (bribes), and he was killed here by the native Nuniwal in the battle — over half a century before the Muslim conquest of Delhi. The dargah built for him has a coffered roof similar to early monuments at Ajmer and Bayana and may have been built during this early period. Some architecture from the time of the Delhi Sultanate survives in Narnaul; the earlier phases are mostly concentrated in and around the dargah complex of Shah Wilayat, while many buildings from the Lodi dynasty are found both in Narnaul itself and on the road to Delhi. These buildings are typically undated.

During medieval period, the native Nuniwal Kshatriyas(Ahir Clan) ruled the area. In 1137 CE, foreign-origin Muslim invader Hazrat Turkman, also known as Shah Wilayat, was killed by the native Nuniwal.

Narnaul is likely the birthplace of the emperor Sher Shah Suri's grandfather Ibrahim Khan Suri; his family is known to have had ties here for multiple generations before him. After his defeat of Humayun in 1540, Sher Shah built a monumental tomb for his grandfather, Ibrahim Khan Suri, inside the dargah complex at Narnaul. This tomb is built in the Lodi architectural style. Later buildings from the Mughal Empire include the Jal Mahal and the octagonal tomb of Shah Quli Khan. An ornate haveli, the Chhata Rai Bal Mukund Das, reflects the "Bengali" architectural style that was spread to northern India at the time of Shah Jahan and was later popular under the Rao Kings of Ahirwal.

In the 1700s, Narnaul variously came under Maratha and Ahir clans control. The Muslim Nawab of Narnaul took part in the Indian Rebellion of 1857 and, after its suppression, the British confiscated his lands and gave them to the Maharaja of Patiala, who had sided with them during the war.

The Battle of Narnaul (also called Battle of Nasibpur) was fought on 16 November 1857, between the British Raj and Aheer forces during the Indian Rebellion of 1857. In 1857, Aheer leader Pran Sukh Yadav of Behror along with Rao Tula Ram, the King of Rewari and Rao Dhan Singh of Charkhi Dadri fought with the British at Nasibpur village near Narnaul. The battle was one of the most ferocious battles of the Indian Rebellion of 1857. ^{[citation needed]}