The name of Bongaigaon is the elongation of a fig and old village named Bongaigaon alias Bong-ai-gaon situated on the southern border of the town. According to hearsay in the long past there were plenty of wild (Bon) Cows (Gai) in the surrounding hilly and forest areas. So, the villagers assembled time to time to drive away the wild cows for protecting their crops. Thus this area was popularly known as Bon-Gai-Gaon.

Originally, Bongaigaon district was under the Judgeship of Goalpara district alongwith Dhubri and Kokrajhar district with headquarter at Dhubri. In the year of 1981 the erstwhile Goalpara district was divided into 3 (three) separate district namely - Goalpara, Dhubri and Kokrajhar. But after division of separate districts, the judicial function of the said districts was under the control of Goalpara district with headquarter at Dhubri, temporarily for few years.

The decision of creating a new district Bongaigaon, curving out some areas of the Goalpara and Kokrajhar district came into existance by the Government of Assam in 1989. And on 29th September, 1989 Bongaigaon was declared a separate district by the Government of Assam with its headquarter at Bongaigaon. more