Cooch Behar district (Bengali: কোচবিহার জেলা, Rajbongshi/Kamatapuri : কোচবিহার) is a district of the state of West Bengal, India, as well as the district's namesake town. During the British Raj, the town of Cooch Behar was the seat of a princely state of Koch Bihar, ruled by the Koch dynasty.

As of 2011 it is the third least populous district of West Bengal (out of 19), after Dakshin Dinajpur and Darjeeling.

The name "Cooch-Behar" is derived from the name of the Koch Rajbongshi tribe that is indigenous to this area. The word "Behar" is the Sanskrit word "Bihar" (to travel) which means the land through which the "Koch Rajbongshi" Kings used to travel or roam about ("Bihar").

The greatest Koch Rajbongshi King that has ever ruled in the Kingdom of Kamatapur is Maharaj Naranarayan, as well as his younger brother Prince Chilaray and other descendents. Historic Kamatapur comprises the total North Bengal maximum parts of Assam, some parts of present Bangladesh, Kishanganj district of Bihar and a few parts of Bhutan. The Koch-Rajbongshi community is demanding a separate state of their own comprising the parts of their old Kingdom to save their centuries-old culture from extinction.

Cooch Behar ( /ˌkuːtʃ bɨˈhɑr/; Bengali: কোচবিহার, Kochbihar ^?[kotʃbihaɾ]) is the district headquarters and the largest city of Cooch Behar District in the Indian state of West Bengal. It is situated in the foothills of the Eastern Himalayas and located at 26°22′N 89°29′E / 26.367°N 89.483°E / 26.367; 89.483. Cooch Behar is the only planned town in North Bengal region with remnants of royal heritage. One of the main tourist destinations in West Bengal, the town is well-known for the Cooch Behar Palace and Madan Mohan Bari temple and has been declared a heritage town. It is also well known for being the maternal home of Maharani Gayatri Devi.

During the British Raj, the town of Cooch Behar was the seat of the princely state of Koch Bihar, ruled by the Koch dynasty. After 20 August 1949, Cooch Behar District was transformed from a princely state to its present status, with the town of Cooch Behar as its headquarters.

The name Cooch-Behar is derived from the name of the Koch or Rajbongshi tribes indigenous to this region for many centuries. The word Behar is derived from Sanskrit: विहार vihara.