Prior to their merger on 26 January, 2020, both the Union Territories of Daman & Diu and Dadra & Nagar Haveli were Portuguese Colonies for almost five centuries. The territory of Dadra & Nagar Haveli was liberated from the Portuguese on 2nd August,1954 whereas the territory of Daman & Diu was liberated on 19th December, 1961. Daman & Diu were administered as part of Union Territory of Goa, Daman & Diu from 19th December between 1961 to 30th May, 1987. In 1987, Daman & Diu became a separate Union Territory, after Goa was made a separate state. Whereas, the territory of Dadra & Nagar Haveli became a separate Union Territory in 1961 after the instrument of Accession was formally signed. During this period there used to be one Police Station in Daman and one Police Station in Diu. Police Department of Daman & Diu was headed by Chief of Police who used to be a DySP/ACP Rank Officer. These Officers used to be deputed from Goa. In the territory of Dadra & Nagar Haveli, there was only one Police Station in Silvassa till 1965. In 1965 two more Police Stations namely Khanvel Police Station and Surangi Police Station were created. Police Department of Dadra & Nagar Haveli was headed by Chief of Police who used to be DySP/ACP Rank Officer who used to be deputed from Gujarat. From 1990s onward, Officers from AGMUT cadre of the Indian Police Service were posted in U.T. of Daman & Diu.
The post of Assistant Inspector General of Police was created in the year 1988 and was upgraded to the post of Deputy Inspector General of Police in the year 2005. Post of Superintendent of Police was created in the Year of 2007 in Dadra & Nagar Haveli whereas Post of Superintendent of Police in Daman & Diu was created in 2008.
On 26th January, 2020, the two Union Territories namely U.T. of Daman & Diu and U.T. of Dadra & Nagar Haveli were merged into a single Union Territory comprising three districts namely Dadra & Nagar Haveli District, Daman District and Diu District. Police Department of U.T. of Dadra Nagar Haveli and Daman & Diu is headed by a Deputy Inspector General of Police of AGMUT Cadre of the Indian Police Service. All three Districts are headed by the Superintendents of Police with one Sub-Division in Daman District, one Sub-Division in Diu District and two functional Sub-Divisions in Dadra & Nagar Haveli District.