Udalguri district (Pron:ˌʊdʌlˈgʊəri), also known as Odalguri, is a district in the Bodoland Territorial Region of the state of Assam in Northeastern India. Udalguri town is the headquarters of the district.

The Bodoland Territorial Region (BTR) is an autonomous division in Assam, India, and a proposed state in Northeast India. It is made up of four districts on the north bank of the Brahmaputra river below the foothills of Bhutan and Arunachal Pradesh. It is administered by an elected body known as the Bodoland Territorial Council which came into existence under the terms of a peace agreement signed in February 2003 and its autonomy was further extended by an agreement signed in January 2020. The region covers an area of over nine thousand square kilometres and is predominantly inhabited by the Bodo people and other indigenous communities of Assam.