The State of Assam is divided into 35 Administrative Districts. The districts are demarcated on the basis of the features such as the rivers, hills, forests, etc. The majority of the newly constituted districts are sub-divisions of the earlier districts. On 15 August 2015, three new districts were formed in addition to former 27 districts which are Charaideo, South Salmara-Mankachar and West Karbi Anglong. On 27 June 2016, Majuli was also declared as a district. Karbi Anglong is the largest district of Assam with nearly 10,434 square kilometers of undivided area followed by Sonitpur with an area of 5324 square kilometers. Majuli carved out of the Northern parts of Jorhat is the first river island district of India. 

The Districts of Assam are further placed under five Regional Divisions. The list of Divisions is as given below:

Each district is headed by the Deputy Commissioner. Generally, an officer belonging to the Indian Administrative Service (IAS) becomes the Deputy Commissioner but occasionally officers belonging to the Assam Civil Service (ACS) too get appointed. The Deputy Commissioner is assisted by a number of officials belonging to different wings of the administrative services of the state like Additional Deputy Commissioner, Sub-divisional Officers, Extra Assistant Commissioners and others.

The Deputy Commissioner also acts as the Collector in case of Revenue matters, as District Magistrate in case of maintenance of Law and Order and General Administration, as District Election Officer in case of conduct of Election and so on. 

Revenue Administration involves collection and fixing of land revenue, registration, mutation and overall management in regard to land matters - private and public. Besides the Revenue Branch of the Deputy Commissioner's Office, which is looked after by the Additional Deputy Commissioner (Revenue), there are 11 outlying Revenue Circles in the district, supervised by Circle Officers. 

As head of the District Administration, the Deputy Commissioner is responsible for all-round developmental activities in the district under various programmes such as MP's Local Area Fund (MPLAD), MLA's fund, Untied Fund, Sub-divisional Plan Scheme Fund, Border Area Development Fund and so on.

The Deputy Commissioner is aided by the Additional Deputy Magistrates (ADM), Sub-Divisional Magistrates (SDM) and Executive Magistrates (EM) for maintenance of Law & Order in the districts. The Circle Officers of the Circles also function as Executive Magistrates and are responsible for maintenance of Law & Order in their respective circle areas. The District Magistrate and other Magistrates take necessary assistance from the Police Department when such necessity arises. The District Police Administration is headed by the Superintendent of Police. 

The following Table comprises of the list of 35 districts of Assam along with the websites: