In Hailuoto municipality, the ultimate decision-making authority is exercised by the 17-member Municipal Council.

Municipal duties are defined in the Constitution and the Local Government Act. In accordance with the section 11 of the Constitution, municipalities have self-government and the right to collect taxes.  According to the Local Government Act, all municipalities shall have Municipal Council, Municipal Board, Mayor, Board of Auditors and a professional auditor. Moreover, Municipal Council may establish boards to manage permanent assignments. In a municipality, the decision-making authority is exercised by Municipal Council elected by residents for four years at a time.