Each one of the three main islands is administered, along with its surrounding minor islands and islets, by an insular council (consell insular in Catalan) of the same name. These four insular councils are the first level of subdivision in the autonomous community (and province) of the Baleares.

Before administrative reform in 1977, Ibiza and Formentera formed a single insular council, covering the whole of the Pitiusic Islands.

The insular council of Mallorca is further subdivided into six comarques; three other comarques cover the same territory as the three remaining insular councils.

These nine comarques are then subdivided into municipalities (municipis), with the exception of Formentera, which is at the same time an insular council, a comarca, and a municipality.

Note that the maritime and terrestrial natural reserves in the Balearic Islands are not owned by the municipalities, even if they fall within their territory, but are owned and managed by the respective insular councils.

Those municipalities are further subdivided into civil parishes (parròquies), that are slightly larger than the traditional religious parishes.

On Ibiza and Formentera parishes are further divided into administrative villages (named véndes in Catalan); each vénda is grouping several nearby hamlets (casaments) and their immediate surroundings. These casaments are traditionally formed by grouping together several cubic houses to form a defensive block with windows open to the east (against heat), sharing their collective precious water resources, whose residents decide and plan common collective works. However, these last levels of subdivisions do not have their own local administration: they are mostly natural economical units for agriculture (and consequently referenced in local norms for constructions and urbanisation as well) and the reference space for families (they may be appended to the names of people and their properties) and are still used in statistics. Historically, these structures had been used for defensive purpose as well and were more tied to the local Catholic church and parishes (notably after the Reconquista).