Darrang is an administrative district in the state of Assam in India. The district headquarters are located at Mangaldoi. The district occupies an area of 3481 km2.

In the 16th century Darrang was subject to the Koch king of Kamarupa, Nara Narayan, and on the division of his dominions among his heirs passed to an independent line of rajas. Early in the 17th century the raja Bali Narayan invoked the aid of the Ahoms of Upper Assam against the Muslim invaders; after his defeat and death in 1637 the Ahoms dominated the whole district. About 1785 the Darrang rajas took advantage of the decay of the Ahom kingdom to try and re-establish their independence, but they were defeated by a British expedition in 1792, and in 1826 Darrang, with the rest of Assam, passed under British control.

In 1983 Sonitpur district was formed from part of Darrang. This was repeated on 14 June 2004 with the creation of Udalguri district.

In 1990 Darrang district became home to Manas National Park, which has an area of 500 km2 (193.1 sq mi). It shares the park with four other districts. It is also home to Orang National Park, which it shares with Sonitpur district. Orang was established in 1999 and has an area of 79 km2 (30.5 sq mi). Apart from the two national parks, it’s also home to a wildlife sanctuary: the Bornadi.

There are four Assam Legislative Assembly constituencies in this district: Kalaigaon, Sipajhar, Mangaldoi, and Dalgaon. Mangaldoi is designated for scheduled castes. All four are in the Mangaldoi Lok Sabha constituency.