Sadiya (, Meaning: Sa-Corpse, Diya-Given) was the third capital of Sutiya Kingdom established by the second Sutiya ruler Ratnadhwajpal in 1248 and remained as the capital till 1524. Extensive remains of buildings and fortifications built during the rule of the Sutiyas near about Sadiya still point to the importance of the region in the past. It is located in the Tinsukia district of the North-eastern Indian state of Assam. Its stands on a grassy plain, nearly surrounded by forested Himalayan mountains, on the right bank of what is locally (but erroneously) considered the main stream of the Brahmaputra river. Sadiya is famous for a flower named sotful (the word means "blessing" or a "desert flower"), which is much like Jasmine.
Sadiya (Vidhan Sabha constituency) is one of the 126 assembly constituencies of Assam a North-eastern state of India. Sadiya is also part of Lakhimpur Lok Sabha constituency.