Formerly part of the First Division, which included Kuching, it became a separate Division on 24 July 1986, with a total area of 4,967.4 square kilometres.

Samarahan Division formerly contained five administrative districts: Samarahan, Asajaya, Serian, Gedong, Sebuyau and Simunjan.

but on 11 April 2015 the Serian District was separated to form a new Division.

The population is Majority of Malay almost 66% and follow by Iban, Chinese, Bidayuh, Melanau, Orang Ulu, Eurasian and Indian.

The declaration took place in Kota Samarahan by the then Premier of Sarawak, Pehin Sri (Dr.) Haji Adenan bin Haji Satem.