The Council of the Isles of Scilly is a sui generis authority in the ceremonial county of Cornwall, England, UK. It is elected every four years.
The Local Government Act 1888 allowed the Local Government Board to establish in the Isles of Scilly "councils and other local authorities separate from those of the county of Cornwall "... for the application to the islands of any act touching local government." Accordingly, in 1890 the Isles of Scilly Rural District Council (the RDC) was formed as a sui generis unitary authority, outside the administrative county of Cornwall. Cornwall County Council provided some services to the Isles, for which the RDC made financial contributions. The Isles of Scilly Order 1930 granted the Council the "powers, duties and liabilities" of a county council. Section 265 of the Local Government Act 1972 allowed for the continued existence of the RDC, but renamed as the Council of the Isles of Scilly.