Sikao district was established in 1887. The present district office was opened 1 March 1987. Sikao District's administrative office is in Bohin Sub-district
The district is divided into five sub-districts, which are further subdivided into 40 villages. There are two townships. Sikao covers parts of tambonBoHin, and Khuan Kun covers parts of Kalase. There are a further five tambon administrative organizations.