Before the reunification of Nepal by Gorkha King Prithvi Narayan Shah, this district was part of the Doti Kingdom.

The majority of the population is ethnic Tharu community, and minor groups are the peoples that have migrated from the northern hilly region.

The district is renowned for Shuklaphanta National Park and the 1,456.97 metres (4,780 ft) long multi-span suspension bridge over Mahakali River.

The main rivers of the region are Mahakali, Jobuda, Chaudhary, Mohana, Syal, Banhara, Sanbora and Doda[5] At the time of the 2011 Nepal census, Kanchanpur District had a population of 451,248.

[8] Ethnicity/caste: 28.8% were Chhetri, 25.8% Tharu, 16.0% Hill Brahmin, 7.7% Kami, 5.6% Thakuri, 3.8% other Dalit, 2.8% Magar, 2.3% Damai/Dholi, 1.6% Sarki, 1.5% Sanyasi/Dasnami, 1.4% Tamang, 0.6% Lohar, 0.4% Gurung, 0.3% Badi, 0.2% Newar, 0.1% Dhanuk, 0.1% Hajam/Thakur, 0.1% Kathabaniyan, 0.1% Kumal, 0.1% Musalman, 0.1% other Terai and 0.1% others.