Cachar, or Kachar, a district of British India, in the province of Eastern Bengal and Assam. It occupies the upper basin of the Surma or Barak river, and is bounded on three sides by lofty hills. Its area is 3769 sq. m. It is divided naturally between the plain and hills. The scenery is beautiful, the hills rising generally steeply and being clothed with forests, while the plain is relieved of monotony by small isolated undulations and by its rich vegetation. The Surma is the chief river, and its principal tributaries from the north are the Jiri and Jatinga, and from the south the Sonai and Daleswari. The climate is extremely moist. Several extensive fens, notably that of Chatla, which becomes lakes in time of flood, are characteristic of the plain. This is alluvial and bears heavy crops of rice, next to which in importance is tea. The industry connected with the latter crop employs large numbers of the population; manufacturing industries are otherwise slight. The Assam-Bengal railway serves the district, including the capital town of Silchar. The population of the district in 1901 was 455,593, and showed a large increase, owing in great part to immigration from the adjacent district of Sylhet. The plain is the most thickly populated part of the district; in the North Cachar Hills the population is sparse.

About 66% of the population are Hindus and 29% Mahommedans. There are three administrative subdivisions of the district: Silchar, Hailakandi and North Cachar. The district takes name from its former rulers of the Kachari tribe, of whom the first to settle here did so early in the 18th century, after being driven out of the Assam valley in 1536, and from the North Cachar Hills in 1706, by the Ahoms. About the close of the 18th century the Burmans threatened to expel the Kachari raja and annex his territory; the British, however, intervened to prevent this, and on the death of the last raja without heir in 1830 they obtained the territory under treaty. A separate principality which had been established in the North Cachar Hills earlier in the century by a servant of the raja, and had been subsequently recognized as such, was taken over by the British in 1854 owing to the misconduct of its rulers. The southern part of the district was raided several times in the 19th century by the turbulent tribe of Lushais.