Sadiya is a town in Tinsukia district, Assam. It was the capital of the Chutia Kingdom and after the downfall of the kingdom it became the seat of the Sadiya-khowa-Gohain of the Ahom kingdom. Extensive remains of buildings and fortifications built during the rule of the Chutias near Sadiya still point to the importance of the region in the past. Historically Sadiya referred to the Chutiya kingdom which included at times the districts of Lakhimpur, Dhemaji and Tinsukia. It is claimed to be the center of development of the eastern Assamese dialects, the inscription here are written in a Tai script. Its stands on a grassy plain, almost surrounded by forested Himalayan mountains, on the right bank of Lohit River which is locally considered the main stream of the Brahmaputra River. The deepest point of the Brahmaputra River is located near this village. It is famous for a flower named satphul, which is much like Jasmine.

Tinsukia district is one of the 34 administrative districts in the state of Assam, India. The district headquarters is located at Tinsukia town. The district occupies an area of 3790 km2.