Much is not known about its early settlements. Scattered and few small villages used to be in the vast and dense forest area of Jhapa. In the 60's and early 70's landscape of Jhapa began to change forever as people from the hills came there to own and cultivate the land under the 'resettlement program'. Eradication of malaria helped change its old name and perception of 'kalapani' into an attractive and fertile place. Fertile land, beautiful landscape, proximity to Nepali speaking part of India, attracted many people there for settlement.No indigenous ethnicity are known to have settled there. Small number of Rajbansi population and some other even smaller in numbers were found to have lived there before the mass migration from various parts of the country and North-eastern part of India and Burma. Jhapa is home to many indigenous ethnic nationalities such as the Limbu, Rai, and Dhimal . Other ethnic groups such as Dhangad, Koche, Rajbanshi, Satar, Meche, Tamang, Uraon, Magar, Gurung, Gangain and many others came to Jhapa in the late 19th century, so did the Hill/mountain castes Bahun, Chhettri, and Newar.
Jhapa is diverse and rich in culture and traditions due to the influences of its different tribes. All the tribes/ethnic groups have their own languages, customs and traditions, and they celebrate their festivals every year.