Jonai Bazar is a census town situated in the Dhemaji district of the northeastern state of India, Assam. It is located in the eastern side of Assam. The town is surrounded by Arunachal Pradesh in the north, Simen in the west, Brahmaputra River in the south and the Sipiya river and Sadiya of Tinsukia district in the east. Jonai Bazar is well connected through buses to some of the important cities in the state which includes Guwahati, Tezpur, North Lakhimpur and Dhemaji. The nearest railway station is the Murkeongselek Railway Station.

The Indian census report of 2001 states that the population of Jonai Bazar is 5172 where males occupy 53% of the population and females constitute the rest 47%. In Jonai Bazar, 16% of the population is less than six years of age. The census report also puts forward the literacy rate. The average literacy rate of Jonai Bazar is 65%, which is higher than the national average literacy rate, which is 59.5%. T o be specific, the male literacy rate is 74% and the female literacy rate is 56%.