The Shire is governed and administered by the Mount Alexander Shire Council; its seat of local government and administrative centre is located at the council headquarters in Castlemaine, it also has service centres located in Maldon and Newstead. The Shire is named after the original name for the Castlemaine region and goldfields.
The council is composed of five wards and seven councillors, with three councillors elected to represent the Castlemaine Ward and one councillor per remaining ward elected to represent each of the other wards.
The council meets in the council chambers at the council headquarters in the Castlemaine Municipal Offices, which is also the location of the council's administrative activities. It also provides customer services at both its administrative centre in Castlemaine, and its service centres in Maldon and Newstead.