Tonk is a town in Rajasthan state, India. The town of Tonk is situated 1462 ft. above sea-level, 60 miles by road south from Jaipur, near the right bank of the Banas River .

Tonk was also a princely state of British India from 1817 to 1947.

The founder of the family was Amir Khan, a Muslim of Afghan descent, who became a notorious Pindari leader at the beginning of the 19th century. He received the territory of Tonk state, and the title Nawab, on submitting to the British in 1817 during the Pindari War. The state was part of the Rajputana agency, and consisted of six isolated tracts, some of which were under the Central India Agency. Total area, 2553 sq. mi; total population (1901), 273,201; estimated revenue £77,000. No tribute was payable. Nawab Mahommed Ibrahim Ali Khan, G.C.I.E., succeeded in 1867, and was one of the few chiefs who attended both Lord Lytton's Durbar in 1877 and the Delhi Durbar of 1903 as rulers of their states. The late minister, Sir Sahibzada Obeidullah Khan , was deputed on political duty to Peshawar during the Tirah campaign of 1897. Grain, cotton, opium and hides were the chief exports. Two of the outlying tracts of the state were served by two railways. Distress was caused by drought in 1899-1900.

In 1901 the town of Tonk, capital of the state, had a population of 38,759. It was surrounded by a wall, with a mud fort. It had a high school, the Walter female hospital under a lady superintendent, and a hospital for males.

Upon India's independence in 1947, the Nawab of Tonk acceded to the Indian government, and the state of Tonk became part of Rajasthan state, while a few of the eastern enclaves of the state became part of Madhya Bharat state.